feat: add Meshery Cloud UI light palette for backward compatibility

[nebula-aac]

Notes for Reviewers

This PR fixes #586

Signed commits

• Yes, I signed my commits.

[sudhanshutech]

i didn't get the purpose of this. @nebula-aac will you please elaborate this

[nebula-aac]

This PR is just a draft as I am testing backward compatibility on using the existing theme palette which is already used in Meshery Cloud UI, and the help migrate to use the new options from the new palette that is already in place. While I did not get much context from previous PRs because there wasn't much and I wasn't around as much to see what were the changes for, I'm also testing style changes and would like to minimize disruption but also allow flexibility to upgrade as needed.

[nebula-aac]

I would like to try and streamline the palette so that it will not cause us to backtrack on something that we may have missed.

When I was testing in the video, this is me removing the global css and removing others that were hiding the styles. While I did not use your approach to change the variables or imports to using a new palette object specific to the project, I did see many blank components which means they needed to be updated according to use the new options from the default palette here in Sistent.