Variables: move state tree into a keyed state (#44642)

* Variables: move state tree into a keyed state

* Update public/app/features/variables/state/transactionReducer.ts

Co-authored-by: kay delaney <45561153+kaydelaney@users.noreply.github.com>

* Chore: fix prettier error

* Chore: renamed slices and lastUid

* Chore: rename toUidAction

* Chore: rename dashboardVariableReducer

* Chore: rename state prop back to templating

* Chore renames variable.dashboardUid

* Chore: rename toDashboardVariableIdentifier

* Chore: rename getDashboardVariable

* Chore: rename getDashboardVariablesState

* Chore: rename getDashboardVariables

* Chore: some more renames

* Chore: small clean up

* Chore: small rename

* Chore: removes unused function

* Chore: rename VariableModel.stateKey

* Chore: rename KeyedVariableIdentifier.stateKey

* user essentials mob! 🔱

* user essentials mob! 🔱

* user essentials mob! 🔱

* user essentials mob! 🔱

Co-authored-by: kay delaney <45561153+kaydelaney@users.noreply.github.com>
Co-authored-by: kay delaney <kay@grafana.com>
Co-authored-by: Alexandra Vargas <alexa1866@gmail.com>
Co-authored-by: Ashley Harrison <ashley.harrison@grafana.com>

public/app/features/variables/pickers/OptionsPicker/reducer.test.ts

@@ -2,7 +2,7 @@ import { cloneDeep } from 'lodash';
 import {
   cleanPickerState,
   hideOptions,
-  initialState as optionsPickerInitialState,
+  initialOptionPickerState as optionsPickerInitialState,
   moveOptionsHighlight,
   OPTIONS_LIMIT,
   optionsPickerReducer,