Export supported function

[kbariotis]

Export the supported function to be used when there is the need to check whether the FS Access API is supported.

https://github.com/excalidraw/excalidraw/pull/3047

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[kbariotis]

@googlebot I signed it!

[nikhilbghodke]

hey @kbariotis , i created another PR for the same issue, i even tested it on excalidraw (inside iframe), i am just checking if we are within a third part environment and returning false in supported function. this will not need any change in excalidraw code base i guess.

also if you feel my approach can work, can you please close this PR and maybe let my PR get merged, as it is kindoff a small dream for a college student like to get a PR merged in some well well used repo :)

[tomayac]

I’ll have a look on Monday (since this is a work project) and merge this. Thanks for the PR.