Implement __repr__ for route classes (#1864)

Implement __repr__ for route classes (#1864)

* implement __repr__ for Route

* implemenr __repr__ for WebSocketRoute, Host, and Mount.

* fix linting issues

* change repr format

* force repr() for inner apps

* Update starlette/routing.py

Co-authored-by: Marcelo Trylesinski <marcelotryle@gmail.com>
* Update starlette/routing.py

Co-authored-by: Marcelo Trylesinski <marcelotryle@gmail.com>
* Update starlette/routing.py

Co-authored-by: Marcelo Trylesinski <marcelotryle@gmail.com>
* Update starlette/routing.py

Co-authored-by: Marcelo Trylesinski <marcelotryle@gmail.com>
* Update tests/test_routing.py

Co-authored-by: Marcelo Trylesinski <marcelotryle@gmail.com>
* Update tests/test_routing.py

Co-authored-by: Marcelo Trylesinski <marcelotryle@gmail.com>
* Update tests/test_routing.py

Co-authored-by: Marcelo Trylesinski <marcelotryle@gmail.com>
* Update tests/test_routing.py

Co-authored-by: Marcelo Trylesinski <marcelotryle@gmail.com>
* Update tests/test_routing.py

Co-authored-by: Marcelo Trylesinski <marcelotryle@gmail.com>
* fix linting issues and tests

* remove repr from Router

Co-authored-by: Marcelo Trylesinski <marcelotryle@gmail.com>