emit a warning if the installed Zig version does not satisfy the minimum_zig_version

[Techatrix]

The build.zig.zon of a project can optionally set the minimum_zig_version field. This is already being used in #230 to resolve which Zig version should be installed. The user may instead manually provide a Zig executable. The extension should check whether the provided Zig's version satisfies the minimum version of the project. If not, a warning message should be displayed.