Fix assorted groovy parsing errors around labels, parentheses, and wh…

…itespace.

Added verification that only whitespace is present within Spaces within parser tests.

Parentheses fixes:
* Type casts inside parentheses
* Constructor invocations inside parentheses

Label fixes:
* Labeled For loops
* Labeled For-each loops

Other whitespace:
* Quoted method declarations
* Semicolon-terminated statements inside switch
* Numeric literals that use 'L', 'd', or 'f' suffixes to specify their type left the specifier in whitespace

Normalization of maven repositories that don't permit directory listi…

…ng (openrewrite#3961)

Add null check. A non null ref can point to a null objectId: (openrew…

…rite#3953)

* Add null check. A non null ref can point to a null objectId:

SymbolicRef[HEAD -> refs/heads/main=0000000000000000000000000000000000000000(-1)]

* cleanup

Find Committers on freshly cloned repositories (openrewrite#3952)

* When a repository is freshly cloned and no other actions have been taken (like pull) ORIG_HEAD is not available. Using HEAD as a fallback works to find the committers.

* null check on ref

Reduce log spam from MavenPomDownloader.

Only send downloadError event when all repositories have failed to be accessed.

Prevent exceptions on missing GradleProject markers (openrewrite#3945)

* Prevent exceptions on missing GradleProject markers

* Restore updating gradle settings in isolation

Add repositoryAccessFailed event to ResolutionEventListener and Maven…

…PomDownloader

Plugin configuration can be null (openrewrite#3931)

Add more evenst to Maven ResolutionEventListener

Improve maven ResolutionEventListener with new event for repository d…

…iscovery, additional information when downloads fail