Prior to this commit, extracting the path within handler mapping would
result in "" if the matching path element would be a Regex and contain
".*". This could cause issues with resource handling if the handler
mapping pattern was similar to `"/folder/file.*.extension"`.
This commit introduces a new `isLiteral()` method in the `PathElement`
abstract class that expresses whether the path element can be compared
as a String for path matching or if it requires a more elaborate
matching process.
Using this method for extracting the path within handler mapping avoids
relying on wildcard count or other properties.
See gh-29712
Fixes gh-29716
777f01d786