refactor(i18n): use common messages for generic button labels (#7020)

A few components defined their own "Cancel", "Close", "Clear" and
"Success" descriptors when commonMessages already has them. Swapped
them over and removed the old ones.

Locale files come from intl:prune-local dropping the now-orphaned
strings across every language.

packages/ui/src/locales/en-US/index.json

@@ -1304,9 +1304,6 @@
   "files.editor.file-saved-title": {
     "defaultMessage": "File saved"
   },
-  "files.editor.find-close": {
-    "defaultMessage": "Close"
-  },
   "files.editor.find-in-file": {
     "defaultMessage": "Find"
   },
@@ -5414,12 +5411,6 @@
   "sharing.invite-players-modal.avatar-alt": {
     "defaultMessage": "{username}'s avatar"
   },
-  "sharing.invite-players-modal.cancel": {
-    "defaultMessage": "Cancel"
-  },
-  "sharing.invite-players-modal.cancel-button": {
-    "defaultMessage": "Cancel"
-  },
   "sharing.invite-players-modal.custom-expiry": {
     "defaultMessage": "Custom..."
   },