fix: export png not support different chart types

[AdityaHegde]

Fixing some issues with export png feature,

1. Support for all chart types.
2. Adding comparison time range.
3. Adding comparison dimension.
4. Generated timestamp in IOS UTC.

Checklist:

• Covered by tests
• Ran it and it works as intended
• Reviewed the diff before requesting a review
• Checked for unhandled edge cases
• Linked the issues it closes
• Checked if the docs need to be updated. If so, create a separate Linear DOCS issue
• Intend to cherry-pick into the release branch
• I'm proud of this work!