Extract SemanticVersion into its own crate (#9956)

This PR extracts the `SemanticVersion` out of `util` and into its own
`SemanticVersion` crate.

This allows for making use of `SemanticVersion` without needing to pull
in some of the heavier dependencies included in the `util` crate.

As part of this the public API for `SemanticVersion` has been tidied up
a bit.

Release Notes:

- N/A

crates/gpui/src/platform/mac/platform.rs

@@ -718,11 +718,11 @@ impl Platform for MacPlatform {
         unsafe {
             let process_info = NSProcessInfo::processInfo(nil);
             let version = process_info.operatingSystemVersion();
-            Ok(SemanticVersion {
-                major: version.majorVersion as usize,
-                minor: version.minorVersion as usize,
-                patch: version.patchVersion as usize,
-            })
+            Ok(SemanticVersion::new(
+                version.majorVersion as usize,
+                version.minorVersion as usize,
+                version.patchVersion as usize,
+            ))
         }
     }