replace final material button with ButtonMain cds component [CV2-3353]

[brianfleming]

Description

Noticed while reviewing tickets we only had one instance of mat button left. This PR completes the process. Since internally we are the primary users of this button I didn't worry too much about retaining the styles perfectly. See the screenshots below.

References: CV2-3353

Type of change

• Performance improvement and/or refactoring (non-breaking change that keeps existing functionality)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Security mitigation or enhancement
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Automated test (add or update automated tests)

How has this been tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can verify the changes. Please describe whether or not you implemented automated tests.

Things to pay attention to during code review

BEFORE

AFTER

Checklist

• I have performed a self-review of my own code
• I've made sure my branch is runnable and given good testing steps in the PR description
• I considered secure coding practices when writing this code. Any security concerns are noted above.
• I have commented my code in hard-to-understand areas, if any
• I have made needed changes to the README
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• If I implemented any new components, they are self-contained, their propTypes are declared and they use React Hooks and, if data-fetching is required, they use Relay Modern with fragment containers
• If my components involve user interaction - specifically button, text fields, or other inputs - I have added a BEM-like class name to the element that is interacted with
• To the best of my knowledge, any new styles are applied according to the design system
• If I added a new external dependency, I included a rationale for doing so and an estimate of the change in bundle size (e.g., checked in https://bundlephobia.com/)
• If I touched a file that included an eslint-disable-file header, I updated the code such that the disabler can be removed

[brianfleming]

FYI reviewers: Marking this as ready for review, but I don't want to merge it until after the next release tagging

[brianfleming]

Thanks @amoedoamorim I am going to merge this after the release.
FYI, i just added one of those small transifex typos reported to this PR to make things easier