profile settings: re-add in condenser

[economicstudio]

I really appreciate this change: https://github.com/steemit/steem/issues/3274 resolved by https://github.com/steemit/steem/pull/3294

So, as you know, now the public profile setting tab should move back to condenser :)

Many newbies are actually quite confused as to how they can change profiles. Previously, it required the active key, which isn't a good idea, but now it only requires the posting key as desired.

So it's time to move the setting tab back to condenser :)

[jredbeard]

After HF21 rolls out we will absolutely move the public profile settings back to condenser.

[roadscape]

The settings tab already exists on condenser, but it only contains the form with localStorage/conveyor saved fields. Need to move the account.json_metadata field form back into condenser, but ensure it uses the account_update2 operation and reads/sets the posting_json_metadata field (not the old json_metadata).

json_metadata requires an active key to update; posting_json_metadata only requires posting key. posting_json_metadata will now be considered authoritative for profile settings.

Base branch: bridge-api

[roadscape]

Here's the commit which removed the functionality: https://github.com/steemit/condenser/commit/9b645cef8c56b5805d60106ac31a21b7e53ace8c#diff-1d5f16d62938cf635cc7d394dc08c582