fix: datamodule can't load files with square brackets in names

[yurijmikhalevich]

What does this PR do?

This PR makes flash.DataModule support files with square brackets (and other glob patterns) in the filenames. More details are in #1500.

Closes #1500.

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[yurijmikhalevich]

Converted to draft because this is missing a test for an URL containing [whatever]

[Borda]

pending on #1501 (comment)

[ethanwharris]

LGTM