Feature request: enable to specify userdata path in ctor of webview::webview

[TsXor]

What OS are you using (uname -a, or Windows version)?

Windows 22H2

What programming language are you using (C/C++/Go/Rust)?

>gcc --version
gcc.exe (x86_64-posix-seh-rev2, Built by MinGW-W64 project) 12.2.0
Copyright (C) 2022 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

What did you expect to see and what you saw instead?

I wanted to specify userdata path in windows, so I located the call to CreateCoreWebView2EnvironmentWithOptions in webview.
Sadly, I found that the userdata path was hardcoded to %APPDATA%\[program executable name].
I think an optional parameter that specify userdata path can be added to webview::webview::webview(bool debug = false, void *wnd = nullptr) in windows. Or at least provide a function to get where userdata went so that I can delete it on request or use some symlink magic.
Not clear about Linux or MacOS backend, but they should have an option to specify userdata path?

[TsXor]

Here is my commit to enable to specify userdata path on Windows: TsXor@52dc59e
I only modified the Windows part, which is not enough for a PR, so I put it here.

[SteffenL]

Thanks for sharing!