* refactor(plugins): use routes specific to the new plugins/admin
* refactor(plugins): remove unused pages (PluginList, PluginItem)
* refactor(plugins): remove PluginPage
* refactor(plugins): remove UpdatePluginModal
* refactor(plugins): move AppConfigWrapper under plugins/admin
* refactor(plugins): move PluginDashboards under plugins/admin
* refactor(plugins): rename the "specs" folder to "tests"
* refactor(plugins): move test files to /tests folder
* refactor(plugins): move AppRootPage into a /components folder
* refactor(plugins): move PluginsErrorsInfo into a /plugins folder
* refactor(plugins): move PluginSettingsCache into a /components folder
* refactor(plugins): move PluginStateInfo into a /plugins folder
* refactor(plugins): move AppRootPage.test.tsx next to the tested component
* refactor(plugins): remove old snapshot tests
* fix(plugins): fix tests
* refactor(plugins/admin): move & rename PluginSettingsCache
* fix(plugins): fix a few rebase issues
* Plugins: remove deprecated code (state handling) (#41739)
* refactor(plugins): use the plugins/admin reducer only
* refactor(plugins): remove tests for the deprecated plugins reducer
* refactor(plugins): remove tests for the deprecated plugins selectors
* refactor(plugins/state): add a short comment note to selectors
* feat(plugins/state): add a selector for selecting errors
* feat(plugins/state): add a hook for getting plugin errors
* refactor(plugins): udpate the PluginsErrorsInfo component to use the new state selectors
* refactor(plugins/state): remove the old (deprecated) selectors
* refactor(plugins/state): use the new actions under /admin
* refactor(plugins/state): remove old (deprecated) reducers and actions
* refactor(plugins): update component definition
* fix(plugins): remove unnecessary {children} prop for PluginsErrorsInfo
* Plugins: show / hide install controls based on the `pluginAdminEnabled` flag (#41749)
* docs(plugins): update documentation for the `plugin_admin_enabled` flag
* refactor(InstallControls): move the main component to a named module
* feat(plugins): use the `pluginAdminEnable` flag to hide / show install controls in the UI
* test(plugins): add tests for enabling/disabling install controls
