Add x64dbg support

[frostworx]

via #winehq irc I just stumbled over the x64dbg debugger.
Would be nice to have automatic support for it in steamtinkerlaunch
(maybe directly using a x64dbg category)

https://bugs.winehq.org/show_bug.cgi?id=45916

Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Software\Wine\AppDefaults\x32dbg.exe]

[HKEY_CURRENT_USER\Software\Wine\AppDefaults\x32dbg.exe\DllOverrides]
"msvcp120"="native,builtin"
"msvcr120"="native,builtin"

[HKEY_CURRENT_USER\Software\Wine\AppDefaults\x64dbg.exe]

[HKEY_CURRENT_USER\Software\Wine\AppDefaults\x64dbg.exe\DllOverrides]
"msvcp120"="native,builtin"
"msvcr120"="native,builtin" 

[frostworx]

What works:

• Can be activated using a "x64dbg" Steam Category
• If x64dbg was not found, download and install the latest snapshot from https://github.com/x64dbg/x64dbg/tags automatically
• Depending on the game binary architecture start either x32dbg or x64dbg
• x64dbg is started automatically with the game binary instead of the regular game start.

This seems to work fine with x32dbg.

What does not work:
- Applying above registry before actually opening x64dbg fails. I assume the reason is that system "regedit" is used, as proton doesn't ship an own one and therefore the WINEPREFIX is confused with a different wine version(?)
** external regedit was removed in favor of wine internal regedit**

- snapshot_2021-02-15_22-35 x64dbg hangs though when opening the game exe (no matter if opened via command line or within the gui).
As soon as the game exe is loaded the whole gui freezes with

0138:fixme:win:FlashWindowEx 0000000000217350 - semi-stub
0138:fixme:thread:QueryThreadCycleTime (0000000000000290,000000000021AAA0): stub!
0198:fixme:dbghelp:dump_unwind_info couldn't read memory for UNWIND_INFO at 7bc82774

Looks like this only happens with proton-GE, but not with official proton.

[frostworx]

Added with f774117