Improves performance by not utf8 encoding the whole query with
encodeUtf8. Only certain parts.
It's also a gradual step needed to use the Snippet type
from hasql-dynamic-statements.
The good part is that protolude 0.3.0 builds with GHC 8.10.
The bad part is that this change is a bit painful:
- the default `toS` has changed to no longer convert to and from ByteString
- similarly, `show` no longer outputs ByteString
The changes here are pretty much minimal to keep things compiling; I didn't
see a nice way to work with the new ConvertText class, even though `toUtf8`
seems like it might help if used besides `toS` at just the right spots.
