Select the proper protocol in the account editor.

* Make sure the proper protocol is select in the account editor.
* Replace `pidgin_protocol_chooser_[gs]et_name` with
`pidgin_protocol_chooser_[gs]et_id`.
* Removed `pidgin_protocol_store_finalize` as it was only used
to disconnect purple signals that we aren't using anymore.

Testing Done:
Compiled and ran locally. Verified via adding a new account, checking a connected account, and a disconnected account.

Bugs closed: PIDGIN-17494

Reviewed at https://reviews.imfreedom.org/r/465/