Determine multi-address- and primary account-related requirements and update PG schema

[ccali11]

Issue
We need to first settle on the user stories / user experiences we intend to deliver with respect to account management. This is not necessarily an exhaustive list of things to consider, but a few that we've run up against that require some thought, requirements setting, and then implementation include:

• setting and updating a user's "primary address"; currently the wallet address of user's first connected wallet becomes a new user on the users table with address being the pk. We should figure out what the best practice should be if we were to update that "primary address" to something else.
• determining if multiple users can share addresses; currently address is the pk on accounts table, so even if two accounts have different owner_addresses (fk to users table), we'd cause a pk collision on the accounts table with our current schema if we were to enable this
• implement a base type naming convention where base types are derived from PG table schema, which then allows us to extend names of the base types with descriptive names to be used in application code

Solution
Determine user story --> user experience --> requirements and write them here. Then implement.

Further Info
I'll be handling this task, but I think everyone will be affected by its outcome so tagging you all (@shanejearley @hawyar @DemogorGod) for awareness. I welcome all thoughts, comments, and feedback, but don't feel obligated. Will run my thought process by at least one of you before implementing.

[ccali11]

Closing issue because it will be resolved in a forthcoming PR.

[ccali11]

Reopening until we close with PR #320