Enable map recycling option when running render tests in GL JS

[brunoabinader]

Enables map recycling option when running render tests in GL JS.

Depends on #5091 to be merged first.

This PR:

• Causes the load event to be fired again when setting a style after a previous set style.
• Enables map recycling in GL JS render tests via options.recycleMap.

[jfirebaugh]

Changing the semantics of the load event would be a significant disruption for existing code; let's find another way to accomplish this.

[brunoabinader]

Changing the semantics of the load event would be a significant disruption for existing code; let's find another way to accomplish this.

@anandthakker suggested we could listen to the 'data' event instead, and check the event payload for e.dataType === 'style'.

[anandthakker]

^ Yep, that should work in the {diff: true} case, but note that if you do map.setStyle(newStyle) without diff: true, that event would only be fired if the diff-and-patch operation fails and we have to fall back to wholesale replacement of the style.

[jfirebaugh]

I think yarn test-render --recycle-map should work, which would make this unnecessary.

[brunoabinader]

This works, but I had to append -- before the script arguments:
yarn test-render -- --recycle-map

[ChrisLoer]

recyrcle-map looks like a typo

[springmeyer]

Is this ready to merge?

[brunoabinader]

Is this ready to merge?

This is stale - requires rebase + logic update to avoid changing load event semantics, as suggested by @jfirebaugh.

[jfirebaugh]

Closing here but without prejudice towards updating with the needed changes and resubmitting -- would be nice to have this.