Check output of every git command when exit code is different than 0

[pmiossec]

to check if it's not due to security issue

Fixes #10816, Fixes #10975, Fixes #11027, Fixes #11039

Improvement on security issue over what has been already done in #10436

Screenshots

Before

After

Test methodology

• Manual (For FormCommit and FormPull)

Test environment(s)

• Git Extensions 33.33.33
• Build bcbc3dd
• Git 2.40.0.windows.1 (recommended: 2.40.1 or later)
• Microsoft Windows NT 10.0.22621.0
• .NET 6.0.16
• DPI 96dpi (no scaling)
• Portable: False
• Microsoft.WindowsDesktop.App Versions

    Microsoft.WindowsDesktop.App 6.0.15 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
    Microsoft.WindowsDesktop.App 6.0.16 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
    Microsoft.WindowsDesktop.App 7.0.5 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Merge strategy

I agree that the maintainer squash merge this PR (if the commit message is clear).

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✒️ I contribute this code under The Developer Certificate of Origin.

[pmiossec]

A better fix than #11055 because it also fixes #10816 ... (i.e. working for all forms started directly with gitex command line options)

[mstv]

Have not run

[RussKie]

Possibly fix #11064 too?