[chore] Fix upload endpoint

[theBeginner86]

Notes for Reviewers

Recent change in Meshery server meshery/meshery#13445 to upload mechanism caused an issue with the plugin. Due to which an empty Kanvas is observed on uploading. Eg: https://raw.githubusercontent.com/layer5labs/meshery-extensions-packages/master/action-assets/helm-plugin-assets/cfa78ee2-f1f8-4d91-ac12-5dcf0aedf0d6.png

This PR updates the endpoint to the new endpoint /api/pattern/import. Now Helm Kanvas Plugin is able to successfully visualize https://raw.githubusercontent.com/layer5labs/meshery-extensions-packages/master/action-assets/helm-plugin-assets/c6370c80-3e32-4399-bdfb-78044f6c687e.png

This PR fixes #

Signed commits

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[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 0.00%. Comparing base (092eb01) to head (3f4052a).
Report is 4 commits behind head on master.

Files with missing lines	Patch %	Lines
cmd/kanvas-snapshot/cmd.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@          Coverage Diff           @@
##           master     #97   +/-   ##
======================================
  Coverage    0.00%   0.00%           
======================================
  Files           4       4           
  Lines         214     212    -2     
======================================
+ Misses        214     212    -2     

Flag	Coverage Δ
unittests	0.00% <0.00%> (ø)

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[theBeginner86]

cc @aabidsofi19

[leecalcote]

😎