Don't hang when GPG hangs

[Ambrevar]

If the init file needs to decrypt .gpg files (e.g. GPG-encrypted bookmarks) but the pinentry hangs for some reason, Next will hang too (simply because it's waiting on pinentry).

A few things we could do:

• Don't block startup because of data-path expansion. Maybe it'd be easy enough to ensure that all data paths are expanded after Next has started, thus giving us the possibility to report which data path failed to expand (e.g. decrypt).

• Add a timeout to the gpg decrypt process.

[aadcg]

Is there a recipe to reproduce this bug?

[aartaka]

Adding content fetching timeouts to nfiles?

[aadcg]

This issue should probably be moved to nfiles.

[Ambrevar]

While Nfiles could potentially do something about this, we need to consider Nyxt startup sequence as part of the problem.

To reproduce:

• Crypt any file read by Nyxt on startup (like the history) with GPG (it must have the same name with .gpg appended).
• Start Nyxt..