Fixed urls with complex URI Path Variables

[altro3]

Fixed #601

[graemerocher]

it feels like a bit of a slippery slope as you have written a mini regex parser in this commit 🤔

[altro3]

@graemerocher The problem is that micronaut does not allow access with parsed URL segments, so there are no other options. Now I can get the entire URL and a list of variable names, so I had to replace all expressions and special characters with the classic definition of variables like these:

{tagId: \\\\d+}  ---> {tagId}
{path:.*}{.ext}  ---> {path}
update{/id:[a-zA-Z]+} ---> update/{id}
{+path} ---> {path}

[altro3]

@graemerocher I don't even know how to do it more correctly, in the current conditions.