servant-client: replace BaseUrl with uri-bytestring

[domenkozar]

Looking at https://hackage.haskell.org/package/servant-client-core-0.13.0.1/docs/Servant-Client-Core-Internal-BaseUrl.html I can think of following benefits/reasons switching to https://hackage.haskell.org/package/uri-bytestring-0.3.1.1/docs/URI-ByteString.html#t:URIRef

a) haskell code around client can use URIRef type to construct the base url and pass it directly to servant-client

b) No changes necessary to servant-client, if for example one chooses to use basic auth (given that's it's mandated by proxy like nginx)

c) uri-bytestring is already a dependency of http-api-data that servant-client-core depends on

d) Removal of BaseUrl and the need to maintain it

Duplicates #139

[phadej]

 @domenkozar title is about uri-bytestring, body is about network-uri.

Note #139 is (mostly) about Links not Client.

[domenkozar]

@phadej fixed.

[tysonzero]

It seems like modern-uri might be a better library to use than uri-bytestring? Haven't done a detailed comparison but I much prefer the use of Text over ByteString for textual data like URIs.

Soostone/uri-bytestring#54

I'm open to arguments in favor of ByteString though, in case there is something I am missing.