[feat] expose version identifiers

[Pessimistress]

Restore version identifiers that were removed in v2.0

After this PR it is possible to get the package version via

import {version} from 'maplibre-gl';

Or with a Map instance:

map.version

See discussion in #1426

Launch Checklist

• Confirm your changes do not include backports from Mapbox projects (unless with compliant license) - if you are not sure about this, please ask!
• Briefly describe the changes in this PR.
• Write tests for all new functionality.
• Document any changes to public APIs.
• Manually test the debug page.
• Suggest a changelog category: bug/feature/docs/etc. or "skip changelog".
• Add an entry inside this element for inclusion in the maplibre-gl-js changelog: <changelog></changelog>.

[HarelM]

Can you please add a test and a change log entry?
I think the 1.x branch had a test for that, that I might have removed, part of the build tests maybe...?

[github-actions]

Bundle size report:

Size Change: +35 B
Total Size Before: 203 kB
Total Size After: 203 kB

Output file	Before	After	Change
maplibre-gl.js	193 kB	193 kB	+35 B
maplibre-gl.css	9.65 kB	9.65 kB	0 B

ℹ️ View Details

No major changes

[birkskyum]

Thank you for looking into this @Pessimistress. I figured out how to do this with typescript, without any rollup replace, and took the liberty to add the unit tests and changelog entry in this pr to get the ball rolling ( #1471 ).