Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

* Refine autonaming to have more intuitive behavior

Last name in an Expression wins, while the first Statement to name wins.
This is done via checking the _id of HasIds during autonaming and only
applying a name if the HasId was created in the scope of autonaming.
There is no change to .autoSeed or .suggestName behavior.

Behavior of chisel3-plugins from before this change is maintained.

* Update docs with naming plugin changes

* Use Data refs for name prefixing with aggregate elements

Vecs set the refs of their elements upon construction of those elements.
In the past, Records haven't set their elements refs until module close,
but it can be done sooner. Doing it upon binding means that refs will at
least be available for Records used in hardware elements. Since only
bound Data can be connected to anyway, Aggregate elements being
connected to will always have a ref which we can then use for creating
naming prefixes.

* Add tighter correctness checks

* Handle more cases in connection prefixing

Add support for forcing setRef to override a previous setting. This
is only used by BlackBox ports which need to drop their io prefix.

Also add a Try() around Data.bindingToString which sometimes throws
exceptions when being used to .toString a Data in an error message.

* Strip trailing spaces in names in compiler plugin

Use caching to reduce number of expensive lookups

* Added documentation. Bugfix in plugin. Moved plugin APIs to separate package

* Revert reg naming behavior (omit underscore)

* Added documentation and a test

* Addressed reviewer feedback.

It must run after the typer, but doesn't need to "run right after". The
stricter dependency conflicted with the semanticdb-typer.