#933: fix: Fixes output of LPUSH command

[Aditya-Chowdhary]

Fixes #933 by returning the length instead of OK.

Minor side change - Integration test for RPUSH used LPUSH command like below, which was fixed

dice/integration_tests/commands/async/deque_test.go

Line 124 in 887d693

cmds: []string{"LPUSH k v", "LPUSH k v1 1 v2 2", "LPUSH k 3 3 3 v3 v3 v3"},

Would also like to point out the existence of a duplicate issue #961

[apoorvyadav1111]

Hi, Thanks for contributing to DiceDB. I have the following suggestions :

1. During the type and encoding check, I think we can remove the check for set data, as we are doing that in the next check anyway. I did some changes in the local for this PR and it was working as expected. However, please test the changes and add scenarios in the tests.
2. We can add more test cases for errors. I could not find much test cases for error, especially when the key is of type set, hmap, json, etc.
   With these suggestions I believe, we will be increasing test coverage for this command.

Thanks.

[lucifercr07]

Closing, merged as part of #969