Syntactic Sugar for writing bloqs

[mpharrigan]

Qualtran is very verbose in its current form. This issue tracks the sub-tasks whose completion may unlock better syntactic sugar

• Restrict what you're allowed to do with a Soquet during bloq building #1720
• SoquetT becomes a protocol #1721
• Make BloqBuilder(add_registers_allowed=True).finalize(...) more obliging #1740
• BloqBuilder.map_soqs behavior when soq is not in map #1742