PULL_REQUEST_TEMPLATE

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*Thank you for submitting a pull request, your contributions are greatly appreciated!*

Please include a summary of the change and which issue is fixed. Please also include relevant motivation and context. 
List any dependencies that are required for this change.
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## Submitter Checklist:

- [ ] Submitted a [ticket](https://github.com/brave/brave-ios/issues) for my issue if one did not already exist.
- [ ] My patch or PR title has a standard commit message that looks like `Fix #123: This fixes the shattered coffee cup!` (or `No Bug: <message>` if no relevant ticket)
- [ ] *Unit Tests* are updated to cover new or changed functionality
- [ ] User-facing strings use `NSLocalizableString()`
- [ ] New files have MPL-2.0 license header.


## Test Plan:

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### Screenshots:

<!-- If your patch includes user interface changes that you would like to suggest or that you would like UX to look at, please include them here. -->


## Reviewer Checklist:

- [ ] PR is linked to an issue via [Zenhub](https://www.zenhub.com/extension).
- [ ] Issues are assigned to at least one epic.
- [ ] Issues include necessary QA labels:
  - [ ] `QA/(Yes|No)`
  - [ ] `release-notes/(include|exclude)`
  - [ ] `bug` / `enhancement`
- [ ] Necessary security reviews have taken place.
- [ ] Adequate test coverage exists to prevent regressions.
- [ ] Adequate test plan exists for QA to validate (if applicable)