Chip specs inconsistencies fixed

[raquelarrojo]

Checklist (Check off all the items before submitting)

• [x] Build process is done without errors. All tests pass in the /lib directory.
• [x] Self-reviewed the code before submitting.
• [x] Meets accessibility standards.
• [x] Added/updated documentation to /website as needed.
• [x] Added/updated tests as needed.

Description Several fixes in chip specs:

• containerPaddingLeft and containerPaddingRight renamed as contentPaddingLeft and contentPaddingRight.
• Changed their values to 16px (instead of 8px) as they are in UI kit and in implementation.
• Added contentPaddingTop and contentPaddingBottom tokens.
• labelMarginLeft and labelMarginRight removed since they do not exist.
• iconSpacing token added.
• Images in specs updated since they were showing 8px in padding instead of 16px.
• Added several color tokens that were left.

Closes #1709