Add support for command HSETNX

[arpitbbhayani]

Add support for the HSETNX command in DiceDB similar to the HSETNX command in Redis. Please refer to the following commit in Redis to understand the implementation specifics - source.

Write unit and integration tests for the command referring to the tests written in the Redis codebase 7.2.5. For integration tests, you can refer to the tests folder. Note: they have used TCL for the test suite, and we need to port that to our way of writing integration tests using the relevant helper methods. Please refer to our tests directory.

For the command, benchmark the code and measure the time taken and memory allocs using benchmem and try to keep them to the bare minimum.

[shreyas23sk]

Hey, I would like to work on this issue.

[arpitbbhayani]

@shreyas23sk Thanks for taking this up. assigned.

[c-harish]

Hi @shreyas23sk, are you still working on this? If not, I would like to take on this.

[shreyas23sk]

Hey @c-harish , I am still working on this. I have made the requisite code changes and will raise the PR soon. Was a bit busy with college.