Improve bisq setup

[chimp1984]

Provides a new AppStartupState class for listening for combined startup states.
Extract domain startup code to a new class to avoid that BisqSetup gets overloaded.

We often need to wait until network and wallet is ready or other combination of startup states.
To avoid those repeated checks for the state or setting of listeners on different domains we provide here a
collection of useful states.

I did not use listeners as we want to query the state as well, so we needed fields keeping the state. Using a BooleanProperty provides both a field for keeping the state as well as a convenient way to add a listener.
E.g.:

appStartupState.walletAndNetworkReadyProperty().addListener((observable, oldValue, newValue) -> {
            if (newValue) {
                ....
            }
        });

[chimp1984]

Codacy does not read comments :-). There is a reason to not make that field local. Please ignore stupid codacy bot.

[ghubstan]

Note to @ghubstan : delete bisq.core.api.StatusCheck after this is merged, use AppStartupState instead.

[chimp1984]

Rebased on master.

[sqrrm]

I'm ready to merge this but will wait for #4568 to get merged first.

[ripcurlx]

I removed the Codacy pattern based on the comment next to the variable. @chimp1984 Please force push to re-trigger Codacy checks. Thanks!

[sqrrm]

ACK

After decision to merge segwit changes directly into release branch, this can now be merged.