Add Bridge v2.0.31

[tsusanka]

We do not wish to release the 2.0.31 as latest, however QA needed it (quite rarely but still) for some testing. More particular they were testing something related to Tor & web and we have allowed the Trezor onion domain in 2.0.30, which is present here but as we know it contained some bugs. I would like to add 2.0.31 here to avoid confusion. The latest will stay on 2.0.27.

@prusnak I believe you have to do this one as the signing via GPG is required.

cc @STew790

[prusnak]

We agreed not to do this, because it is possible to run trezord as a standalone binary using the following command (in the macOS Terminal, providing the Suite is installed in the Applications):

'/Applications/Trezor Suite.app/Contents/Resources/bin/bridge/trezord' 

(quotes are required because there is a space between "Trezor" and "Suite" in the path)

For Linux and Windows the process should be very similar.