checkstyle-10.12.1

Checkstyle 10.12.1 - https://checkstyle.org/releasenotes.html#Release_10.12.1

Bug fixes:

#13140 - SimplifyBooleanExpressionCheck throw NullPointerException while checking ternary operator

Other Changes:

Move Filters and File Filters to be a sibling of Checks in site menu
Create tests from xdoc examples
Remove redundant check name in anchor
Resolve pitest survivals in modules
Extend checkstyle-examples-checks
Split modules' xdoc into separate pages
Create separate ant-phase-verify execution for xdocs-examples
Mobile page rendering requires extra font difference for properties
Ensure category index page tables are in sync with checks.xml page table
Fail linkcheck on internal broken site link
Fix broken anchors in subdirectories/subpages
doc: update AbstractClassName examples to match tests
Resolve pitest for FinalLocalVariableCheck
Resolves Pitest for VariableDeclarationUsageDistanceCheck
doc: update ConstantName examples to match tests
Resolves Pitest for DeclarationOrderCheck
Resolves Pitest for AbstractSuperCheck
Create initial xdocs-test folder structure