Removed fallback on web for drawAtlas

[wolfenrain]

Description

Initial testing if the fallback for the drawAtlas method is still needed for the web.

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[luanpotter]

I tested this on chrome mobile mode on desktop.

main:

testing-draw-atlas-on-web:

I believe this means:

• both the fallback and the normal impl works on web now
• so the fallback (that that doesn't work on devices) is no longer needed
• however the normal implementation clearly shows the tile gap issue for the particular size/zoom I used. but that is a known issue unrelated to anything that the fallback just happened to fix.

[spydon]

I tested this on chrome mobile mode on desktop.

main:

testing-draw-atlas-on-web:

I believe this means:

• both the fallback and the normal impl works on web now
• so the fallback (that that doesn't work on devices) is no longer needed
• however the normal implementation clearly shows the tile gap issue for the particular size/zoom I used. but that is a known issue unrelated to anything that the fallback just happened to fix.

Maybe we can leave it as a selectable mode called something else then?

[luanpotter]

LGTM