ui: add mock-up for license selector form - custom license builder

[davidgamez]

Summary:

Summarize the changes in the pull request including how it relates to any issues (include the #number, or link them).

Expected behavior:

Explain and/or show screenshots for how you expect the pull request to work in your testing (in case other devices exhibit different behavior).

Testing tips:

Provide tips, procedures and sample files on how to test the feature.
Testers are invited to follow the tips AND to try anything they deem relevant outside the bounds of the testing tips.

Please make sure these boxes are checked before submitting your pull request - thanks!

• Run the unit tests with ./scripts/api-tests.sh to make sure you didn't break anything
• Add or update any needed documentation to the repo
• Format the title like "feat: [new feature short description]". Title must follow the Conventional Commit Specification(https://www.conventionalcommits.org/en/v1.0.0/).
• Linked all relevant issues
• Include screenshot(s) showing how this pull request works and fixes the issue(s)

[github-actions]

*Lighthouse ran on https://mobility-feeds-dev--pr-1368-oa4gu75a.web.app/ * (Desktop)
⚡️ HTML Report Lighthouse report for the changes in this PR:

Performance	Accessibility	Best Practices	SEO
🟠 70	🟢 100	🟢 100	🟢 100

*Lighthouse ran on https://mobility-feeds-dev--pr-1368-oa4gu75a.web.app/feeds * (Desktop)
⚡️ HTML Report Lighthouse report for the changes in this PR:

Performance	Accessibility	Best Practices	SEO
🟠 77	🟢 91	🟢 100	🟢 100

*Lighthouse ran on https://mobility-feeds-dev--pr-1368-oa4gu75a.web.app/feeds/gtfs/mdb-2126 * (Desktop)
⚡️ HTML Report Lighthouse report for the changes in this PR:

Performance	Accessibility	Best Practices	SEO
🟠 86	🔴 0	🟢 96	🟢 100

*Lighthouse ran on https://mobility-feeds-dev--pr-1368-oa4gu75a.web.app/feeds/gtfs_rt/mdb-2585 * (Desktop)
⚡️ HTML Report Lighthouse report for the changes in this PR:

Performance	Accessibility	Best Practices	SEO
🟢 94	🟠 88	🟢 100	🟢 100

*Lighthouse ran on https://mobility-feeds-dev--pr-1368-oa4gu75a.web.app/gbfs/gbfs-flamingo_porirua * (Desktop)
⚡️ HTML Report Lighthouse report for the changes in this PR:

Performance	Accessibility	Best Practices	SEO
🟢 100	🟢 100	🟢 100	🟢 100

[github-actions]

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