Plugins: Support for link extensions (#61663)

* added extensions to plugin.json and exposing it via frontend settings.

* added extensions to the plugin.json schema.

* changing the extensions in frontend settings to a map instead of an array.

* wip

* feat(pluginregistry): begin wiring up registry

* feat(pluginextensions): prevent duplicate links and clean up

* added test case for link extensions.

* added tests and implemented the getPluginLink function.

* wip

* feat(pluginextensions): expose plugin extension registry

* fix(pluginextensions): appease the typescript gods post rename

* renamed file and will throw error if trying to call setExtensionsRegistry if trying to call it twice.

* added reafactorings.

* fixed failing test.

* minor refactorings to make sure we only include extensions if the app is enabled.

* fixed some nits.

* Update public/app/features/plugins/extensions/registry.test.ts

Co-authored-by: Levente Balogh <balogh.levente.hu@gmail.com>

* Update packages/grafana-runtime/src/services/pluginExtensions/registry.ts

Co-authored-by: Levente Balogh <balogh.levente.hu@gmail.com>

* Update packages/grafana-runtime/src/services/pluginExtensions/registry.ts

Co-authored-by: Levente Balogh <balogh.levente.hu@gmail.com>

* Update public/app/features/plugins/extensions/registry.test.ts

Co-authored-by: Levente Balogh <balogh.levente.hu@gmail.com>

* Moved types for extensions from data to runtime.

* added a small example on how you could consume link extensions.

* renamed after feedback from levi.

* updated the plugindef.cue.

* using the generated plugin def.

* added tests for apps and extensions.

* fixed linting issues.

* wip

* wip

* wip

* wip

* test(extensions): fix up failing tests

* feat(extensions): freeze registry extension arrays, include type in registry items

* added restrictions in the pugindef cue schema.

* wip

* added required fields.

* added key to uniquely identify each item.

* test(pluginextensions): align tests with implementation

* chore(schema): refresh reference.md

---------

Co-authored-by: Jack Westbrook <jack.westbrook@gmail.com>
Co-authored-by: Levente Balogh <balogh.levente.hu@gmail.com>

packages/grafana-data/src/types/config.ts

@@ -76,16 +76,6 @@ export interface UnifiedAlertingConfig {
   minInterval: string;
 }
 
-/**
- * Describes the plugins that should be preloaded prior to start Grafana.
- *
- * @public
- */
-export type PreloadPlugin = {
-  path: string;
-  version: string;
-};
-
 /** Supported OAuth services
  *
  * @public
@@ -199,7 +189,6 @@ export interface GrafanaConfig {
   /** @deprecated Use `theme2` instead. */
   theme: GrafanaTheme;
   theme2: GrafanaTheme2;
-  pluginsToPreload: PreloadPlugin[];
   featureToggles: FeatureToggles;
   licenseInfo: LicenseInfo;
   http2Enabled: boolean;

packages/grafana-data/src/types/index.ts

@@ -45,7 +45,6 @@ export type {
   GrafanaConfig,
   BuildInfo,
   LicenseInfo,
-  PreloadPlugin,
 } from './config';
 export type { FeatureToggles } from './featureToggles.gen';
 export * from './alerts';