Switch to the Web Crypto API for generating SHA checksums

[jelly]

This allows us to drop the two pure JavaScript implementations of SHA-1 and SHA-256. These native Web Crypto API is available as baseline and allows us to easily switch over to SHA-512 without adding a new dependency.

[martinpitt]

This looks good, thanks! Did you check that the computed checksums are the same before and after? (Do our tests validate that and compare to some CLI output?) Can you please refresh/fix the node_modules build?

[jelly]

For development I basically did a sit() in TestStorageNBDE as that's the easiest to get tang and everything setup.

So on Fedora it defaults to SHA-256 and this is validated by getting the hash from tang-show-keys. On RHEL 8 or 9 this might still default to SHA-1.

So one of them is tested in CI, tang-show-keys is a simple bash script which parses the JWT token (like we do in JS). But you can't override if you want SHA1 or SHA-256.

                b.wait_in_text("#dialog", "Check the key hash with the Tang server")
                b.wait_in_text("#dialog", tang_m.execute("tang-show-keys").strip())
                testlib.sit()

[martinpitt]

Eeexcellent, dankjewel!

[cockpituous]

These 2 added lines are not executed by any test.

[cockpituous]

These 2 added lines are not executed by any test.