Fully normalizes the baseUrl behaviour to better match how this sort of
feature works in other programs.
1. The baseUrl is always appended to paths, even the built-in `/emby`
and `/mediabrowser` paths.
2. The baseUrl is set statically at class instance creation, to ensure
it persists through changes until the next restart.
3. Configuration is normalized using a function when set, to ensure it's
in a standard `/mypath` format with leading `/`.
4. Cleans up the conditionals around default redirects. For sanity after
changing the URL, it will match *any* path that doesn't match the
current baseUrl and redirect it back to the main page (with baseUrl).
5. Adds a second method, NormalizeUrlPath, to avoid lots of `+ "/" +`
string manipulations which are unclean - we should always have a leading
slash.
6. Sets the default baseUrl to an empty string to avoid unexpected
behaviour, though this would be worked-around automatically.
7. Adds some debug logs whenever a URL is normalized, to help track down
issues with this code (if any arise).
2a79ae0a6e