Support for regex based placeholder

[webysther]

I have a simple use case: Portainer

The url is base only in fragment: https://example.com/#!/52/docker/stacks/shlink?id=875&type=2&regular=true&orphaned=false&orphanedRunning=false

No dynamic will work because the full url after base url is based only in fragment, a placeholder strategy will be nice to allow this:

short: https://url.example.com/?endpoint=52&stack=875
long: https://example.com/#!/52/docker/stacks/shlink?id=875&type=2&regular=true&orphaned=false&orphanedRunning=false

Allow pure string change base on placeholder will work like this:

1. https://url.example.com/?endpoint={{endpoint}}&stack={{stack}}
2. Internally shlink convert to regex group
3. Add to https://example.com/#!/{{endpoint}}/docker/stacks/shlink?id={{stack}}&type=2&regular=true&orphaned=false&orphanedRunning=false