[ahdigital][1] Enable creating a new committee member via GUI?

Similar to how recently the worker proposal system had GUI functionality added for the creation of worker proposals, perhaps it'd be worth enabling creating a committee member via the GUI so that more committee members (who may not be technically able to run a full/cli node) may have a chance at becoming a committee member? We've only got 11 committee members to vote from at the moment which isn't great.

Currently the only instructions on how to create a committee member is:

> create_committee_member account "url" true

http://docs.bitshares.org/bitshares/tutorials/committee-member-create.html

Start by comparing the existing worker proposal GUI flow with the `create_committee_member account "url" true` command described in the issue and the linked committee-member documentation. Done means committee members can be created through the GUI without running a full or CLI node, with the required account, URL, and confirmation information supported.

Written by the indexing model from the issue text.