Support AllowReserved in Path Implementation

[lmazuel]

No description provided.

[weidongxu-microsoft]

reopen

Find our current implementation of x-ms-skip-url-encoding is not same as the URI template Reserved Expansion.

When input is /foo/bar/a b, our core keeps it unchanged, while URI template would ask for /foo/bar/a%20b (space is percentage-coded)

[weidongxu-microsoft]

Currently use same impl of x-ms-skip-url-encoding.

If we need to improve. it likely be same for both.