This PR adds context-based `k=v` splits based
on the sub-system which was obtained, if the
keys are not provided an error will be thrown
during parsing, if keys are provided with wrong
values an error will be thrown. Keys can now
have values which are of a much more complex
form such as `k="v=v"` or `k=" v = v"`
and other variations.
additionally, deprecate unnecessary postgres/mysql
configuration styles, support only
- connection_string for Postgres
- dsn_string for MySQL
All other parameters are removed.
