Added Oracle DB Extractor

[keenborder786]

• Please merge this, I really this. I have added support for Oracle DB in dbcat to get the metadata.

[keenborder786]

Please merge this.

[SyedBaqarAbbas]

I need this feature too, you are a lifesaver!

[hussnainahmed]

+1

[ahmedrayn]

I need this feature as well.

[vrajat]

Thanks for the contribution @keenborder786 . The code looks good to me. Can you add a couple of tests?

• Add another entry to connections.yaml. You'll also have to add corresponding asserts in test_add_sources
• Add an OracleExtractor test similar to test_snowflake_extractor

These should be easy to add. I'll accept and merge it once the tests run successfully. Also can you confirm that you've tested the changes on an oracle db? I dont have one to test with.

[keenborder786]

@vrajat okay.

[vrajat]

I've merged #67 as it used servicename and _create_sqlalchemy_extractor in the diff. I see that the NOT IN clause is not the same. Can you check and see if that requires a change?