expose the `jsonSchemaRegistry` in the extension API

[Kosta-Github]

I would like to request to expose the jsonSchemaRegistry in the public API for extensions.

The interface IJSONContributionRegistry is defined here:

vscode/src/vs/platform/jsonschemas/common/jsonContributionRegistry.ts

Lines 19 to 55 in b68fa59

	export interface IJSONContributionRegistry {
	readonly onDidChangeSchema: Event<string>;
	readonly onDidChangeSchemaAssociations: Event<void>;
	/**
	* Register a schema to the registry.
	*/
	registerSchema(uri: string, unresolvedSchemaContent: IJSONSchema, store?: DisposableStore): void;
	registerSchemaAssociation(uri: string, glob: string): IDisposable;
	/**
	* Notifies all listeners that the content of the given schema has changed.
	* @param uri The id of the schema
	*/
	notifySchemaChanged(uri: string): void;
	/**
	* Get all schemas
	*/
	getSchemaContributions(): ISchemaContributions;
	getSchemaAssociations(): { [uri: string]: string[] };
	/**
	* Gets the (compressed) content of the schema with the given schema ID (if any)
	* @param uri The id of the schema
	*/
	getSchemaContent(uri: string): string | undefined;
	/**
	* Returns true if there's a schema that matches the given schema ID
	* @param uri The id of the schema
	*/
	hasSchemaContent(uri: string): boolean;
	}

I would like to be able to do the same as the internal LanguageModelToolsService is doing here but within an extension:

vscode/src/vs/workbench/contrib/chat/browser/languageModelToolsService.ts

Lines 126 to 127 in b68fa59

	jsonSchemaRegistry.registerSchema(schemaUrl, toolData.inputSchema, store);
	store.add(jsonSchemaRegistry.registerSchemaAssociation(schemaUrl, `/lm/tool/${toolData.id}/tool_input.json`));

1. first register a new schema
2. associate that schema with a specific file in the workspace/editor

I cannot use the contributes.jsonValidation (in package.json) for this, since I need to construct a JSON schema on-the-fly depending on the content of the to-be-analyzed JSON file and the JSON file itself doesn't have a specific filename pattern that could be used with the contributes.jsonValidation mechanism.

If the internal jsonSchemaRegistry as defined here:

vscode/src/vs/workbench/contrib/chat/browser/languageModelToolsService.ts

Line 41 in b68fa59

const jsonSchemaRegistry = Registry.as<JSONContributionRegistry.IJSONContributionRegistry>(JSONContributionRegistry.Extensions.JSONContribution);

would be exposed I could register and unregister the JSON schemas with the different files dynamically/on-the-fly. This would also solve this feature request over here: #230136

Pseudo code would look like this:

const jsonSchemaRegistry: IJSONContributionRegistry = vscode....getJsonSchemaRegistry();

...
const unregisterAssocCb = jsonSchemaRegistry.registerSchemaAssociation(schemaUri, fileUri);

...
unregisterAssocCb();