Secrets: encryption encryption storage uses versioning (#108036)

* Secrets: delete unused FakeKeeper

* Secrets: encrypted value storage stores versions

* add version to span

* trigger build

* remove ineffectual assignment

* lint

* drop secret_encrypted_value.uid / add name and version columns

pkg/storage/secret/encryption/testdata/mysql--encrypted_value_delete-delete.sql

@@ -1,4 +1,6 @@
 DELETE FROM `secret_encrypted_value`
-WHERE `namespace` = 'ns' AND
-  `uid`      = 'abc123'
+WHERE 
+  `namespace` = 'ns' AND
+  `name`      = 'n1' AND
+  `version`   = 1
 ;