Add working_dir to PlanPluginInput

[Warashi]

What this PR does / why we need it:

As discussed in this comment, I add the working_dir field to the PlanPluginInput message.

Which issue(s) this PR fixes:

Fixes #

Does this PR introduce a user-facing change?:

• How are users affected by this change:
• Is this breaking change:
• How to migrate (if breaking change):

[Warashi]

@khanhtc1202
I think the working dir passed to the plugin should contain the deploy source.
On the other hand, this working_dir is used with os.MkdirTemp, so we should not place the deploy source at the root of this directory.
So, I documented that the deploy source is placed within the directory named "deploy_source."
WDYT?

[khanhtc1202]

I think that's fine 👍

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 22.46%. Comparing base (d362879) to head (131fcee).
Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5043      +/-   ##
==========================================
+ Coverage   22.45%   22.46%   +0.01%     
==========================================
  Files         522      522              
  Lines       57041    57041              
==========================================
+ Hits        12809    12816       +7     
+ Misses      43204    43198       -6     
+ Partials     1028     1027       -1     

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[Warashi]

I think it's simpler than this PR to pass the DeploySource information directly to the plugin.
So we start from that point and then pass workspace_dir, working_dir, temp_dir, or something similar if we need it.