Upgrade/braze web sdk

[aashishmalik]

Description of the change

Update Braze SDK from v2 to v4

Type of change

• [-] Breaking change (fix or feature that would cause existing functionality to not work as expected)

Related issues

Fix #1

Checklists

Development

• [ ] Lint rules pass locally
• [ ] The code changed/added as part of this pull request has been covered with tests
• [ ] All tests related to the changed code pass in development

Code review

• [ ] This pull request has a descriptive title and information useful to a reviewer. There may be a screenshot or screencast attached
• [ ] "Ready for review" label attached to the PR and reviewers mentioned in a comment
• [ ] Changes have been reviewed by at least one other engineer
• [ ] Issue from task tracker has a link to this pull request

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This change is 

[utsabc]

Looks good we will push this once we are ready with change-log along with list of customers who will be affected