[PM-25660] UserKeyDefinition.clearOn doesn't clear data in some cases (#16799)

* fix: always try to register clearOn events

`registerEvents` already checks for existing registered events so there is no
need to have a pre-check in `doStorageSave`. It causes issues because the
`newState` and `oldState` parameters come from the custom deserializer which
might never return `null` (e.g. transforming `null` to some default value).
Better to just use the list of registered events as a source of truth.

A performance check shows that most calls would only save a couple of
milliseconds (ranges from 0.8 ms to 18 ms) and the total amount of time
saved from application startup, to unlock, to showing the vault is about 100 ms.
I haven't been able to perceive the change.

* Revert "feat: add folder.clear warning (#16376)"

This reverts commit a2e36c4489.

libs/common/src/key-management/vault-timeout/services/vault-timeout.service.ts

@@ -144,7 +144,6 @@ export class VaultTimeoutService implements VaultTimeoutServiceAbstraction {
 
     await this.searchService.clearIndex(lockingUserId);
 
-    // ! DO NOT REMOVE folderService.clearDecryptedFolderState ! For more information see PM-25660
     await this.folderService.clearDecryptedFolderState(lockingUserId);
     await this.masterPasswordService.clearMasterKey(lockingUserId);
 

libs/state-internal/src/default-single-user-state.ts

@@ -31,8 +31,6 @@ export class DefaultSingleUserState<T>
 
   protected override async doStorageSave(newState: T, oldState: T): Promise<void> {
     await super.doStorageSave(newState, oldState);
-    if (newState != null && oldState == null) {
-      await this.stateEventRegistrarService.registerEvents(this.keyDefinition);
-    }
+    await this.stateEventRegistrarService.registerEvents(this.keyDefinition);
   }
 }