build(gulpfile): remove iife and umd support

this package target only the backend env so iife and umd are no longer required. base on this change
lot of stuff is now unused, and clean up will come in next commits.

BREAKING CHANGE: remove iife and umd bundles

gulpfile.js

@@ -296,7 +296,7 @@ gulp.task( 'build', ( done ) => {
             n: 'Itee.Server',
             i: path.join( __dirname, 'sources', `${packageInfos.name}.js` ),
             o: path.join( __dirname, 'builds' ),
-            f: 'esm,cjs,iife,umd',
+            f: 'esm,cjs',
             e: 'dev,prod',
             s: true,
             t: true