* rewrite `Models.ExternalTool` to use `_execArgsGenerator` instead of `OpenCmdArgs` and `ArgTransform`
* remove dependency of `System.Linq` due to AOT limitations
* since the `Visual Studio` is only available on Windows, use `TryAdd` directly.
* update `README.md`
BREAKING CHANGE: now the key in `external_editors.json` uses the same name with external tool.
Signed-off-by: leo <longshuang@msn.cn>
* remove `string.IsNullOrEmpty(OS.ShellOrTerminal)` checking from detail backend since it has been checked by `Native.OS.OpenTerminal`
* remove `ViewModels.Preference.IsTerminalConfigured` because it is only used by itself (Unlike `IsGitConfigured`).
* add `Native.OS.TestShellOrTerminal` and use it instead of setting `Preference.ShellOrTerminal` directly, because we have binded a callback that will save preference into file when its property changed. It may cause lag in some enviroments if we saving preference into file too frequently (see PR #436).
* run `dotnet format`
* input font name directly instead of a font picker because localized font family name is not supported by Avalonia
* fallback monospace font to default font
* remove unused code
code_review:
* use JsonSerializerContext to avoid AOT warnnings
* since we call TryAdd by interating the installed tools, so detecting by environment variable becomes meaningless (it can not detect tools not installed by Toolbox). Just add it into founded directly
* remove unnecessary type defines
* determine the Icon used by tool while adding it to the founded list.
# Conflicts:
# src/Native/Linux.cs
# src/Native/MacOS.cs
# src/Native/Windows.cs
* remove dotnet-tool.json because the project does not rely on any dotnet tools.
* remove Directory.Build.props because the solution has only one project.
* move src/SourceGit to src. It's not needed to put all sources into a subfolder of src since there's only one project.
