Spike: Research and plan the changes necessary to migrate to SQLite

[smcintyre-r7]

We need to plan the work to migrate to SQLite. In order to close this ticket we need:

• New tickets created here on GitHub that break the work for framework down into separate units
• At least one ticket to make sure the necessary changes are in place for Metasploit Pro
• A concrete determination on what to do with postgresql, do we A) keep it as it is, B) just remove it from the installers and use sqlite so there's less to maintain C) remove it entirely D) something else?

[adfoster-r7]

This should build on: #19852