Use short commit hash in "snapshot" build artifact archive filename

When you have multiple snapshot builds on your computer for testing purposes, it's difficult to keep track of which is which. The commit hash is shown by the running application, but it's more convenient to have the installation also identified by its folder name.

Adding the short commit hash to the build archive filename (and thus the extracted folder name) provides a clear identifier for each build.

Before this change, the archive is named like:
arduino-pro-ide_snapshot_Linux_64bit.zip

after:
arduino-pro-ide_0.0.7-snapshot.1b8c510_Linux_64bit.zip

electron/packager/config.js

@@ -15,7 +15,7 @@ function artifactName() {
         } else if (isNightly) {
             return `nightly-${timestamp()}`
         } else {
-            return 'snapshot';
+            return getVersion();
         }
     })();
     const name = 'arduino-pro-ide';