build: package api-extractor and -model (#9920)

* fix(ExceptText): don't display import("d..-types/v10"). in return type

* Squashed 'packages/api-extractor-model/' content from commit 39ecb196c

git-subtree-dir: packages/api-extractor-model
git-subtree-split: 39ecb196ca210bdf84ba6c9cadb1bb93571849d7

* Squashed 'packages/api-extractor/' content from commit 341ad6c51

git-subtree-dir: packages/api-extractor
git-subtree-split: 341ad6c51b01656d4f73b74ad4bdb3095f9262c4

* feat(api-extractor): add api-extractor and -model

* fix: package.json docs script

* fix(SourcLink): use <> instead of function syntax

* fix: make packages private

* fix: rest params showing in docs, added labels

* fix: missed two files

* fix: cpy-cli & pnpm-lock

* fix: increase icon size

* fix: icon size again

packages/api-extractor/src/analyzer/AstEntity.ts

@@ -0,0 +1,46 @@
+// Copyright (c) Microsoft Corporation. All rights reserved. Licensed under the MIT license.
+// See LICENSE in the project root for license information.
+
+/**
+ * `AstEntity` is the abstract base class for analyzer objects that can become a `CollectorEntity`.
+ *
+ * @remarks
+ *
+ * The subclasses are:
+ * ```
+ * - AstEntity
+ *   - AstSymbol
+ *   - AstSyntheticEntity
+ *     - AstImport
+ *     - AstNamespaceImport
+ * ```
+ */
+export abstract class AstEntity {
+	/**
+	 * The original name of the symbol, as exported from the module (i.e. source file)
+	 * containing the original TypeScript definition.  Constructs such as
+	 * `import { X as Y } from` may introduce other names that differ from the local name.
+	 *
+	 * @remarks
+	 * For the most part, `localName` corresponds to `followedSymbol.name`, but there
+	 * are some edge cases.  For example, the ts.Symbol.name for `export default class X { }`
+	 * is actually `"default"`, not `"X"`.
+	 */
+	public abstract readonly localName: string;
+}
+
+/**
+ * `AstSyntheticEntity` is the abstract base class for analyzer objects whose emitted declarations
+ * are not text transformations performed by the `Span` helper.
+ *
+ * @remarks
+ * Most of API Extractor's output is produced by using the using the `Span` utility to regurgitate strings from
+ * the input .d.ts files.  If we need to rename an identifier, the `Span` visitor can pick out an interesting
+ * node and rewrite its string, but otherwise the transformation operates on dumb text and not compiler concepts.
+ * (Historically we did this because the compiler's emitter was an internal API, but it still has some advantages,
+ * for example preserving syntaxes generated by an older compiler to avoid incompatibilities.)
+ *
+ * This strategy does not work for cases where the output looks very different from the input.  Today these
+ * cases are always kinds of `import` statements, but that may change in the future.
+ */
+export abstract class AstSyntheticEntity extends AstEntity {}