Rework how AT references and completion work

AtGotoDeclarationHandler is replaced by proper PsiReferences

Author: RedNesto

changelog.md

@@ -6,6 +6,12 @@
 
 - `plugin.yml`, `paper-plugin.yml` and `bungee.yml` main class reference and validity inspection
 
+### Changed
+
+- Overhauled Access Transformer support:
+  - many lexing errors should now be fixed
+  - class names and member names now have their own references, replacing the custom Goto handler
+
 ## [1.8.1] - 2024-08-10
 
 ### Added