Issue with pb_auth token: if it expires, the Wallet misbehaves and the user needs to log out

[andrea-dintino]

(writing with @puria )

UPDATE: we just redeployed and it seems that the ISSUE is not true

ISSUE:

• At each stop and start, pb generates a secret key. The secret key is used to sign the pb_auth JWT.
• Currently, if the wallet stores a JWT authToken that is invalid, and pb doesn't accept it, the wallet doesn't have a mechanism to get a new token.

The wallet must be modified so that:

• it must store email and password
• when it tries to access pb with the token it has stored
• IF pb returns an error, the wallet must send AGAIN email and password, to receive a new JWT. This must happen WITHOUT logging the user out
• Then new JWT will overwrite the existing one

For this refactoring, tests must be written first.