fix: add keep alive logic for xlinectl lock command

[Phoenix500526]

Closes: #664

Please briefly answer these questions:

• what problem are you trying to solve? (or if there's no problem, what's the motivation for this change?) fix issue #664

• what changes does this pull request make?

1. remove the lease client from LockClient
2. add keep alive logic for xlinectl lock cmd

• are there any non-obvious implications of these changes? (does it break compatibility with previous versions, etc)

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 16.66667% with 30 lines in your changes are missing coverage. Please review.

Project coverage is 75.22%. Comparing base (e35b35a) to head (138250e). Report is 28 commits behind head on master.

Files	Patch %	Lines
crates/xlinectl/src/command/lock.rs	0.00%	14 Missing :warning:
...xline-test-utils/src/bin/validation_lock_client.rs	0.00%	9 Missing :warning:
crates/xlinectl/src/command/lease/keep_alive.rs	0.00%	6 Missing :warning:
crates/xline-client/src/clients/lock.rs	83.33%	1 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #666      +/-   ##
==========================================
- Coverage   75.55%   75.22%   -0.34%     
==========================================
  Files         180      182       +2     
  Lines       26938    26990      +52     
  Branches    26938    26990      +52     
==========================================
- Hits        20353    20302      -51     
- Misses       5366     5428      +62     
- Partials     1219     1260      +41     

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[Phoenix500526]

Closed since it's duplicated with pr #820