Switch away from jwt

[jalil-salame]

jwt is unmaintained, the PRs and issues are not being addressed and there have been no updates in the last two years.

The alternatives I found are:

• jwt-simple: less popular but on active development, currently supports wasm
• jsonwebtoken: more popular (than jwt even), is in the process of introducing wasm support

I found this while looking at my transitive dependencies (and why base64 v0.13 was being pulled in).

[thomastaylor312]

Thanks for the heads up here