feat: add support for encrypted ssh key and ssh-agent

[wangl-cc]

Closes #334

[codecov]

Codecov Report

Attention: Patch coverage is 51.26050% with 58 lines in your changes missing coverage. Please review.

Project coverage is 65.18%. Comparing base (3fd7bfa) to head (8ac72a6).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
maa-cli/src/installer/resource.rs	0.00%	35 Missing ⚠️
maa-cli/src/config/cli/resource.rs	72.61%	23 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #337      +/-   ##
==========================================
+ Coverage   65.15%   65.18%   +0.02%     
==========================================
  Files          44       44              
  Lines        3556     3645      +89     
==========================================
+ Hits         2317     2376      +59     
- Misses       1239     1269      +30     

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