Move toolregistry package to pkg/plugin

[khanhtc1202]

What this PR does:

as title

Why we need it:

All the plugin shared packages should be placed under pkg/plugin and we can public it as the based for creating new plugin later.

Which issue(s) this PR fixes:

Part of #4980

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]

👍🏻

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 25.81%. Comparing base (73db7c2) to head (f91db1d).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5415      +/-   ##
==========================================
- Coverage   25.82%   25.81%   -0.02%     
==========================================
  Files         449      449              
  Lines       48472    48472              
==========================================
- Hits        12517    12511       -6     
- Misses      34978    34984       +6     
  Partials      977      977              

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