Add globe/mercator button

[wipfli]

Launch Checklist

Adds a button for choosing the projection globe or mercator. Appears under the light settings. Live demo is here: https://wipfli.github.io/maputnik/?layer=1455082206%7E0&modal=settings#1.02/0/0

• Briefly describe the changes in this PR.
• Link to related issues.
• Include before/after visuals or gifs if this PR includes visual changes.
• Write tests for all new functionality.
• Add an entry to CHANGELOG.md under the ## main section.

[HarelM]

I would recommend adding a test...

[wipfli]

Do you mind helping me with the test? I don't know cypress but happy to learn about it if you can help me a bit

[HarelM]

sure, this repo has a good practice when it comes to end-to-end tests.
There's the driver which is the low level usage of cypress, usually, you won't need to touch it:
https://github.com/maplibre/maputnik/blob/main/cypress/e2e/maputnik-driver.ts
There's the helper which obscures how the UI looks and facilitate function to use in the tests so that the tests should look like a flow given-when-then style, but it's very slim in this case:
https://github.com/maplibre/maputnik/blob/main/cypress/e2e/maputnik-cypress-helper.ts
And there's the relevant test, since you added your functionality in a modal I would start by looking at a similar test here:
https://github.com/maplibre/maputnik/blob/main/cypress/e2e/modals.cy.ts

Let me know if the above is enough or not.
Thanks!