Improve PR Action

[Jikoo]

PR action always builds Maven project even if only resource pack is affected.
PR action never builds resource pack.

PR action should build Maven project unless only resource pack files are modified. This should include all prior changes so a successful resource pack build doesn't give a misleading green check to a failing Maven build. We may need to grab more git history to determine that (I believe we use a shallow clone for speed); I'm unsure if GitHub checks only the current commit or all changes when using paths/paths-ignore.
PR action should build resource pack if resource pack or actions are modified.