feat: add lightning cli dynamically

[aniketmaurya]

What does this PR do?

Let users run LitServe models using the Lightning CLI.

• After SDK installation the litserve's lightning command is replaced from the SDK CLI.

Before submitting

• Was this discussed/agreed via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure to update the docs?
• Did you write any new necessary tests?

PR review

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[codecov]

Codecov Report

Attention: Patch coverage is 72.72727% with 3 lines in your changes missing coverage. Please review.

Project coverage is 89%. Comparing base (3947e07) to head (d0346d2).
Report is 2 commits behind head on main.

Additional details and impacted files

@@         Coverage Diff         @@
##           main   #446   +/-   ##
===================================
- Coverage    89%    89%   -0%     
===================================
  Files        31     32    +1     
  Lines      2041   2052   +11     
===================================
+ Hits       1824   1832    +8     
- Misses      217    220    +3     

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