[Refactor] Init wallet parameters interaction

[furszy]

This PR does two things:

1. Move the pwalletMain object inside the wallet.h file.
2. Move the wallet's parameters initialization to an static method ParameterInteraction in the wallet class.

This is coming (partially) from upstream 25340b7 .

[random-zebra]

Code ACK.
Just minor concerns about some code duplication between wallet and init. E.g the UIError/UIWarning static functions in wallet have almost the same implementation of InitError/InitWarning functions (also static) in init.cpp. Wouldn't it be better to export them from wallet and use them during init as well?
Actually, imo they don't even belong to the wallet file, really: should be in some "util" file, and imported from there both in wallet and init.

[furszy]

You know, I thought on that but then thought on the translation context for the AmountErrMsg method, which will need to receive the parent or make the util file depend on guiinterface (which is not good, util.h shouldn't have any GUI dependency).

Good catch on the InitError and InitWarning. I missed them completely.

[random-zebra]

which will need to receive the parent or make the util file depend on guiinterface

why? AmountErrMsg is only a string utility (takes a char pointer and a string to return a new string). It has no dependency with guiinterface (UIError and UIWarning do).

[furszy]

The _ before the parenthesis is a translation function call which is part of guiinterface.

[random-zebra]

Right.
Well, couldn't this be directly inlined in guiinterface then?

[furszy]

it could but not really the file's responsibility. That file should be clean as possible from utility functions.
We should have guiinterfaceutil or well, need to check if guiutil.h is suited for this or not.

[random-zebra]

I don't think guiutil.h is a good place either. Would introduce unneeded dependencies in other files.
Probably a separate util file (in src, not in src/qt) would be better.

[furszy]

Updated.

[random-zebra]

ACK d452a2d

[Fuzzbawls]

ACK 831834c