feat: stage channels (#5456)

* feat: add stage channel type

* feat: initialise stage channel structure

* feat: add STAGE_MODERATOR permissions bitfield

* fix: typo in permissions

* fix(Channel): type selection logic

* feat: add rtcRegion to StageChannel and VoiceChannel

* feat: rtc region editing for stage and voice channels

* feat: stage channel userLimit

* feat: add stage channels to exports

* feat: add computed properties to stage channel

* feat(VoiceState): include stage channel in docs

* feat: allow ability to join stage channels

* feat(StageChannel): join and leave methods

* docs: add StageChannel link in GuildChannel docs

* feat(VoiceState): suppress and requestToSpeakTimestamp

* feat(StageChannel): setRequestToSpeak

* refactor(StageChannel): update setRequestToSpeak

* feat(VoiceState): add moveToSpeakers and moveToAudience

* feat(VoiceState): add methods to move in/out of speakers

* feat(VoiceState): add stage channel sanity checks

* feat(Permissions): add REQUEST_TO_SPEAK

* feat(VoiceState): simpler methods

* docs(VoiceState): add documentation for new methods

* refactor: remove unused error message

* chore: remove debug statements

* chore: revert changes to package-lock.json

* docs(VoiceState): clarify suppress

* docs(VoiceState): add missing @type param

* feat(StageChannel): remove nsfw property

* fix(VoiceState): check permissions in channel

Co-authored-by: Advaith <advaithj1@gmail.com>

* fix(VoiceState): instantiate error with new

Co-authored-by: BannerBomb <BannerBomb55@gmail.com>

* refactor(VoiceState): more readable API route builder

Co-authored-by: Sugden <28943913+NotSugden@users.noreply.github.com>

* style(VoiceState): fix lint errors

* docs(VoiceState): add example usage for new methods

* docs: setRTCRegion examples

* chore: update typings

* fix(VoiceState): calculate permissions for self

* refactor(VoiceState): tidy up implementation

* Update src/structures/VoiceState.js

Co-authored-by: Jan <66554238+vaporox@users.noreply.github.com>

* refactor: vaporox's suggestions

* style(VoiceState): fix linter errors

* chore: update typings

* chore: remove unused error message

* refactor(VoiceState): use optional chaining

Co-authored-by: Sugden <28943913+NotSugden@users.noreply.github.com>

* chore: move getters below constructor in typings

* refactor(StageChannel): optional chaining

Co-authored-by: Sugden <28943913+NotSugden@users.noreply.github.com>

* style(VoiceState): fix lint errors

* docs: fix incorrect types

Co-authored-by: izexi <43889168+izexi@users.noreply.github.com>

* Update src/structures/VoiceChannel.js

Co-authored-by: izexi <43889168+izexi@users.noreply.github.com>

* Update src/structures/VoiceChannel.js

Co-authored-by: izexi <43889168+izexi@users.noreply.github.com>

* refactor(VoiceState): use optional chaining

Co-authored-by: Sugden <28943913+NotSugden@users.noreply.github.com>

* refactor(StageChannel): remove permission override check in joinable

* refactor: make ChannelTypes a proper enum

* Use createEnum

Co-authored-by: izexi <43889168+izexi@users.noreply.github.com>

* chore: remove unused code from Constants

* refactor(StageChannel): remove unnecessary getters

* chore: update typings

* refactor: introduce BaseGuildVoiceChannel class

* refactor(VoiceChannel): reduce code duplication

* feat: export BaseGuildVoiceChannel

* chore: update typings

* docs: fix typos

* refactor: move setRTCRegion to BaseGuildVoiceChannel

* feat(VoiceState): remove permission checks

* chore: update typings

* Apply suggestions from code review

Co-authored-by: Sugden <28943913+NotSugden@users.noreply.github.com>
Co-authored-by: Jan <66554238+vaporox@users.noreply.github.com>

* chore: update esm exports and typings

* Update src/structures/VoiceState.js

Co-authored-by: Vlad Frangu <kingdgrizzle@gmail.com>

Co-authored-by: Advaith <advaithj1@gmail.com>
Co-authored-by: BannerBomb <BannerBomb55@gmail.com>
Co-authored-by: Sugden <28943913+NotSugden@users.noreply.github.com>
Co-authored-by: Jan <66554238+vaporox@users.noreply.github.com>
Co-authored-by: izexi <43889168+izexi@users.noreply.github.com>
Co-authored-by: Vlad Frangu <kingdgrizzle@gmail.com>

src/structures/GuildChannel.js

@@ -18,6 +18,7 @@ const Util = require('../util/Util');
  * - {@link CategoryChannel}
  * - {@link NewsChannel}
  * - {@link StoreChannel}
+ * - {@link StageChannel}
  * @extends {Channel}
  * @abstract
  */
@@ -319,6 +320,7 @@ class GuildChannel extends Channel {
    * @property {OverwriteResolvable[]|Collection<Snowflake, OverwriteResolvable>} [permissionOverwrites]
    * Permission overwrites for the channel
    * @property {number} [rateLimitPerUser] The ratelimit per user for the channel in seconds
+   * @property {?string} [rtcRegion] The RTC region of the channel
    */
 
   /**
@@ -374,6 +376,7 @@ class GuildChannel extends Channel {
         nsfw: data.nsfw,
         bitrate: data.bitrate || this.bitrate,
         user_limit: typeof data.userLimit !== 'undefined' ? data.userLimit : this.userLimit,
+        rtc_region: typeof data.rtcRegion !== 'undefined' ? data.rtcRegion : this.rtcRegion,
         parent_id: data.parentID,
         lock_permissions: data.lockPermissions,
         rate_limit_per_user: data.rateLimitPerUser,
@@ -594,7 +597,7 @@ class GuildChannel extends Channel {
    */
   get manageable() {
     if (this.client.user.id === this.guild.ownerID) return true;
-    if (this.type === 'voice') {
+    if (this.type === 'voice' || this.type === 'stage') {
       if (!this.permissionsFor(this.client.user).has(Permissions.FLAGS.CONNECT, false)) {
         return false;
       }