LibraryPanels: removes feature toggle (#33839)

* WIP: intial structure

* Refactor: adds create library element endpoint

* Feature: adds delete library element

* wip

* Refactor: adds get api

* Refactor: adds get all api

* Refactor: adds patch api

* Refactor: changes to library_element_connection

* Refactor: add get connections api

* wip: in the middle of refactor

* wip

* Refactor: consolidating both api:s

* Refactor: points front end to library elements api

* Tests: Fixes broken test

* LibraryPanels: removes feature toggle

* Fix: fixes delete library elements in folder and adds tests

* Tests: fixes snapshot

* Refactor: adds service interfaces so they can be easily mocked

* Refactor: changes order of tabs in manage folder

* Refactor: fixes so link does not cover whole card

* Refactor: fixes index string name

* Update pkg/services/libraryelements/libraryelements.go

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

* Update pkg/services/libraryelements/libraryelements_permissions_test.go

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

* Update pkg/services/libraryelements/database.go

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

* Chore: changes after PR comments

* Update libraryelements.go

* Update libraryelements.go

* Chore: updates after PR comments

* Chore: trying to fix build error

* Refactor: fixed stupid mistake

* Update libraryelements.go

* Chore: tries to fix build errors

* Refactor: trying to fix MySQL key length

* Update libraryelements.go

* Update pkg/services/libraryelements/libraryelements.go

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

* Update pkg/services/librarypanels/librarypanels.go

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

* Refactor: changes after PR comments

* Refactor: changes after PR comments

* Tests: fixes tests

* Refactor: renames connections to connectedDashboards

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

pkg/setting/setting.go

@@ -399,11 +399,6 @@ func (cfg Cfg) IsHTTPRequestHistogramEnabled() bool {
 	return cfg.FeatureToggles["http_request_histogram"]
 }
 
-// IsPanelLibraryEnabled returns whether the panel library feature is enabled.
-func (cfg Cfg) IsPanelLibraryEnabled() bool {
-	return cfg.FeatureToggles["panelLibrary"]
-}
-
 type CommandLineArgs struct {
 	Config   string
 	HomePath string