Add fallback for any apps still using handleClick

[dancork]

What does this PR do? (please provide any background)

What tests does this PR have?

Add test for onClick and regression test for handleClick.

How can this be tested?

Fireup any tripapp using master (local, staging or production) Make a carpark search for LGW and on availability select a non-flexible product No upsell modal will fire

On your local machine pull this branch On your local tripapp npm link your local ui-toolkit ( probably npm link ../ui-toolkit ) Fire up tripapp and do the same search. An upsell modal should now fire

Screenshots / Screencast

What gif best describes how you feel about this work?

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• [x] I have checked our general contributing document and the project specific contributing document (if present) and I'm happy for this to be reviewed.

  Reviewers

Review 1

• [ ] :+1:

Review 2

• [x] :+1:

Review 3

• [ ] :+1:

By adding a +1 you are confirming you have...

• Witnessed the work behaving as expected (this could be on the author's machine or screencast).
• Checked for coding anti-patterns.
• Checked for appropriate test coverage.
• Checked all the tests are passing.

[cameronviner]

Taking Review

[cameronviner]

Looks good to me 👍

[rahulpatel]

Nice! 👍 ✌️