Improve type annotations

[rsokl]

This PR further improves our internal type annotations:

• Use TypeAlias to make our various aliases explicit
• Update Partial to reflect latest type stub in pyright
• hydra_zen.typing._builds_overloads now exposes protocols instead of overloaded function stubs
• Various builds overloads are corrected to eliminate overlapping overload warnings from pyright-strict
• Various builds overloads are corrected to provide sufficiently-general annotations; tests included
• Excessive overloads removed from get_target and instantiate
• Eliminate overlapping overloads for instantiate
• builds now uses the __foo convention to make hydra_target positional-only
• Enable pyright-strict on select files that supply important types/overloads
• move make_builds_fn definition to its own file; simplify overloads; get rid of hacky overload method; enforce pyright-strict

(despite these improvements, mypy still crashes when we run on src/: python/mypy#12322)