[refactor] pass config object instead of pass db/ef params

[gasolin]

alternative proposal to replace https://github.com/embedchain/embedchain/pull/100

1. pass config object instead of pass separate params (db, ef), which is expected to extend more
2. add default_model in config time (could add another method to overwrite in query time though)

[cachho]

We're currently discussing which route to take for configuration. I agree that it needs to change from how it is right now.

[cachho]

take a look at #156 and PR #158, that's most likely the route were taking for configuration.

[gasolin]

replaced by #158