Dramatically simplify the UnnecessarilyQualified check

[carterkozak]

Before this PR

See #2997

Previously we did a rather invasive search on every MemberSelectTree.

After this PR

Now, we first check that the symbol is a type, and the select is operating upon a package, ruling out unnecessary treepath traversals and import scans.

==COMMIT_MSG==
Dramatically simplify the UnnecessarilyQualified error-prone check
==COMMIT_MSG==

[changelog-app]

Generate changelog in changelog/@unreleased

What do the change types mean?

• feature: A new feature of the service.
• improvement: An incremental improvement in the functionality or operation of the service.
• fix: Remedies the incorrect behaviour of a component of the service in a backwards-compatible way.
• break: Has the potential to break consumers of this service's API, inclusive of both Palantir services
  and external consumers of the service's API (e.g. customer-written software or integrations).
• deprecation: Advertises the intention to remove service functionality without any change to the
  operation of the service itself.
• manualTask: Requires the possibility of manual intervention (running a script, eyeballing configuration,
  performing database surgery, ...) at the time of upgrade for it to succeed.
• migration: A fully automatic upgrade migration task with no engineer input required.

Note: only one type should be chosen.

How are new versions calculated?

• ❗The break and manual task changelog types will result in a major release!
• 🐛 The fix changelog type will result in a minor release in most cases, and a patch release version for patch branches. This behaviour is configurable in autorelease.
• ✨ All others will result in a minor version release.

Type

• Feature
• Improvement
• Fix
• Break
• Deprecation
• Manual task
• Migration

Description

Dramatically simplify the UnnecessarilyQualified error-prone check

Check the box to generate changelog(s)

• Generate changelog entry

[carterkozak]

Some may prefer for this to end up as Entry rather than Map.Entry, but I'd argue that either one is better than java.util.Map.Entry (and I prefer to list enclosing classes rather than importing them, but that's a stylistic choice).

[autorelease3]

Released 6.10.0

[ash211]

Thank you for this change -- it reduced UnnecessarilyQualified time by over 100x on an internal repo!

Before:

UnnecessarilyQualified                           : 12.412000 seconds (17.41%) 

After:

UnnecessarilyQualified                           : 108 millis       (0.74%)

An unscientific test -- there other changes in the repo than just this change. But it is vastly better now, and I'm going to turn this back on.