Port JWT fix from 3.6 to 3.5

[ewhanson]

With changes introduced in pkp/pkp-lib#10435, an update was made to handling JWTs in the JatsTemplateDownloadHandler the should be back-ported to stable-3_5_0.

PRs:

• jatsTemplate: pkp/jatsTemplate#117 Port JWT from 3.6 to 3.5 #118

[ewhanson]

Hey @kaitlinnewson, would you be able to have a quick look at this? It's porting some minor changes in the way JWTs are decoded that was already added to main in pkp/pkp-lib#10435. Thanks!

[kaitlinnewson]

Hi @ewhanson, I've noted one small change in the PR, otherwise it looks good to me.