Make sure we get fw version before submitting tx request

[alex-miller-0]

For Lattices on fw >0.15.0 we make a different type of signing request. We only do this when this.sdkSession.getFwVersion() shows that we are >0.15.0.

However, we only sync firmware version for connect, not for syncWallet. Thus, the first request returns an "Invalid Request" error from the device. After a connect call, the second request works fine.

We don't need to worry about this yet because 0.15.0 won't be released for a little while but we should get a fix in before that happens.

What we should really do is update firmware to return the wallet UID in connect, then deprecate the fetchActiveWallet route and switch _syncWallet in the keyring for _connect.

[alex-miller-0]

_syncWallet was removed and replaced with _connect in #36 so we can close this