fix: stop using is3dSupported

[rachel-fenichel]

The basics

• I branched from develop
• My pull request is against develop
• My code follows the style guide
• I ran npm run format and npm run lint

The details

Resolves

Part of #6325

Proposed Changes

Stop checking whether translate3d is supported--it's fine on all browsers in 2022.
Deprecate is3dSupported in preparation for deleting it.

Behavior Before Change

Checked for support using a variety of browser prefixes, because there was not a standard way to check.

Behavior After Change

Always assume it's supported and act accordingly.

Reason for Changes

Remove workarounds for old browser behaviour.

Test Coverage

Checked in Chrome and Firefox.
I made the change in several pieces so that I could check functionality at an intermediate point.

Documentation

None

Additional Information

We might be able to make block and workspace drag surfaces always get built, or else decide they don't improve performance and delete them entirely. Either case would be nice since it would let us reduce the number of available code paths. But that's tricky because it requires performance analysis and because the block and drag surfaces are currently optional arguments to the (public) WorkspaceSvg constructor.

[BeksOmega]

...or else decide they don't improve performance and delete them entirely... But that's tricky because it requires performance analysis

Already did the performance analysis: #6160 They do not improve performance :/