Multiple Formats in a Text Field

[riastrad]

Resolves #985

This PR adds a new example that demonstrates how to to use multiple formats within a SymbolLayer's textField.

[langsmith]

@riastrad , https://docs.mapbox.com/mapbox-gl-js/example/display-and-style-rich-text-labels/ could be good to reference if you wanna' see how the expressions are used. All of these wild text label examples are basically more about setting default, fallbacks, etc. with expressions, than anything else.

[riastrad]

@langsmith this basically done (let's say 98%). I'll be updating the example's menu card image tomorrow morning and then it should be good to merge 🚀

[langsmith]

[riastrad]

This should be good to go, @langsmith!

Also noting that I dropped this in a very similar location as the new example in #982, so whichever example merges second should gird itself for the probability of merge errors in MainActivity.java & AndroidManifest.xml.

[langsmith]

Great work @riastrad . I pushed a commit, which imports some methods to improve the readability of the code, so that there are fewer instances of Expression. throughout the code.

[riastrad]

Thanks for the review, @langsmith. This is ready for another quick pass as soon as you're ready.

[langsmith]

🍠

[langsmith]

Looks good!