Thumbnail wazero integrate

[storybehind]

Changes

• API to generate thumbnail of given image. Accepts three parameters.
  Thumbnail(img []byte, width, height int)
img -> byte array of image,
  width and height -> width and height of expected thumbnail image in pixels,

• If it results in error, the second parameter (error) will be error message of string type.

• Otherwise, the second parameter will always be null. The first parameter contains byte array of thumbnail image.

NOTE: The first parameter will be empty array if it's unsuccessful (e.g couldn't generate due to unsupported format). This can be used as a fallback mechanism to generate thumbnail in the frontend.

benchmark image.txt

Fixes

Tests

Tasks to complete before merging PR:

• Ensure system tests are passing. If not Run them manually to check for any regressions 📋
• Do any new system tests need added to test this change? do any existing system tests need updated? If so create a PR at 0chain/system_test
• Merge your system tests PR to master AFTER merging this PR

Associated PRs (Link as appropriate):

• blobber:
• 0chain:
• system_test:
• zboxcli:
• zwalletcli:
• Other: ...