Chore: Fix all Typescript strict null errors (#26204)

* Chore: Fix typescript strict null errors

* Added new limit

* Fixed ts issue

* fixed tests

* trying to fix type inference

* Fixing more ts errors

* Revert tsconfig option

* Fix

* Fixed code

* More fixes

* fix tests

* Updated snapshot

* Chore: More ts strict null fixes

* More fixes in some really messed up azure config components

* More fixes, current count: 441

* 419

* More fixes

* Fixed invalid initial state in explore

* Fixing tests

* Fixed tests

* Explore fix

* More fixes

* Progress

* Sub 300

* Now at 218

* Progress

* Update

* Progress

* Updated tests

* at 159

* fixed tests

* Progress

* YAy blow 100! at 94

* 10,9,8,7,6,5,4,3,2,1... lift off

* Fixed tests

* Fixed more type errors

Co-authored-by: Ryan McKinley <ryantxu@gmail.com>

public/app/features/dashboard/components/FolderPicker/FolderPickerCtrl.ts

@@ -146,7 +146,8 @@ export class FolderPickerCtrl {
     const rootFolder: { text: string; value: any } = { text: this.rootName, value: 0 };
 
     this.getOptions('').then((result: any[]) => {
-      let folder: { text: string; value: any };
+      let folder: { text: string; value: any } | undefined;
+
       if (this.initialFolderId) {
         // @ts-ignore
         folder = _.find(result, { value: this.initialFolderId });