feat: remove datastores and implement Managers (#3696)

* Initial commit: add 5 initial managers

- Base manager
- GuildChannelManager
- MessageManager
- PresenceManager
- Reaction Manager
- Added LimitedCollection

* Add GuildEmojiManager, various fixes

* Modify some managers and add guildmembermanager

* Initial integration

* Delete old stores

* Integration part two, removed LRUCollection

- Most of the integration has been finished
- TODO typings
- Removed LRUCollection, needless sweeping

* Typings + stuff i somehow missed in ChannelManager

* LimitedCollection typings/ final changes

* Various jsdoc and syntactical fixes, Removed Util.mixin()

* tslint fix

* Grammatical and logical changes

* Delete temporary file placed by mistake

* Grammatical changes

* Add missing type

* Update jsdoc examples

* fix: ChannelManager#remove should call cache#delete not cache#remove

* fix recursive require

* Fix missed cache in util

* fix: more missed cache

* Remove accidental _fetchMany change from #3645

* fix: use .cache.delete() over .remove()

* fix: missing cache in ReactionCollector

* fix: missed cache in client

* fix: members is a collection not a manager

Co-Authored-By: Sugden <28943913+NotSugden@users.noreply.github.com>

* fix: various docs and cache fixes

* fix: missed cache

* fix: missing _roles

* Final testing and debugging

* LimitedCollection: return the Collection instead of undefined on .set

* Add cache to BaseManager in typings

* Commit fixes i forgot to stage yesterday

* Update invite events

* Account for new commit

* fix: MessageReactionRemoveAll should call .cache.clear()

* fix: add .cache at various places, correct return type

* docs: remove mentions of 'store'

* Add extra documented properties to typings

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

docs/examples/greeting.js

@@ -19,7 +19,7 @@ client.on('ready', () => {
 // Create an event listener for new guild members
 client.on('guildMemberAdd', member => {
   // Send the message to a designated channel on a server:
-  const channel = member.guild.channels.find(ch => ch.name === 'member-log');
+  const channel = member.guild.channels.cache.find(ch => ch.name === 'member-log');
   // Do nothing if the channel wasn't found on this server
   if (!channel) return;
   // Send the message, mentioning the member