Migrate channel spec to ChannelModule subclass (first proof of concept)

[isaacroldan]

WHY are these changes introduced?

Fixes #0000

WHAT is this pull request doing?

How to test your changes?

Post-release steps

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes
• I've considered analytics changes to measure impact
• The change is user-facing, so I've added a changelog entry with pnpm changeset add

[isaacroldan]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• Migrate channel spec to ChannelModule subclass (first proof of concept) #7294 👈 (View in Graphite)
• Wire loader to support ModuleRegistry alongside ExtensionSpecification #7293
• Rename ApplicationModule to ExtensionInstance, old class to SpecificationBackedExtension #7292
• Introduce ApplicationModule base class, ModuleDescriptor, and ModuleRegistry #7291
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

[github-actions]

Differences in type declarations

We detected differences in the type declarations generated by Typescript for this branch compared to the baseline ('main' branch). Please, review them to ensure they are backward-compatible. Here are some important things to keep in mind:

• Some seemingly private modules might be re-exported through public modules.
• If the branch is behind main you might see odd diffs, rebase main into this branch.

New type declarations

We found no new type declarations in this PR

Existing type declarations

packages/cli-kit/dist/public/node/node-package-manager.d.ts

@@ -68,14 +68,6 @@ export declare function packageManagerFromUserAgent(env?: NodeJS.ProcessEnv): Pa
  * @returns The dependency manager
  */
 export declare function getPackageManager(fromDirectory: string): Promise<PackageManager>;
-/**
- * Builds the command and argv needed to execute a local binary using the package manager
- * detected from the provided directory or its ancestors.
- */
-export declare function packageManagerBinaryCommandForDirectory(fromDirectory: string, binary: string, ...binaryArgs: string[]): Promise<{
-    command: string;
-    args: string[];
-}>;
 interface InstallNPMDependenciesRecursivelyOptions {
     /**
      * The dependency manager to use to install the dependencies.