Improve Error Handling for FacebookConnectButton

[arunshenoy99]

Proposed changes

1. Return standard error object as an argument to the onFailure function.
2. Remove console.error's.

This goes with: newfold-labs/wp-module-onboarding#571

Type of Change

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Checklist

• I have read the CONTRIBUTING doc
• Linting and tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments

[ramyakrishnai]

@manikantakailasa can you please check this PR with your code changes in BH plugin and approve this PR ?