feat(glob): export glob api alias (#45195)

This is beign reported by Danger CI tests now as missing export surface
for the module. No existing api was changed.
Reference:
https://git.io/Jf6lU

Thanks!

types/glob/glob-tests.ts

@@ -1,5 +1,7 @@
 import glob = require("glob");
 const Glob = glob.Glob;
+// ExpectType glob
+const globAlias = glob.glob;
 
 (() => {
     const pattern = "test/a/**/[cg]/../[cg]";

types/glob/index.d.ts

@@ -21,6 +21,7 @@ declare namespace G {
 
     function hasMagic(pattern: string, options?: IOptions): boolean;
 
+    let glob: typeof G;
     let Glob: IGlobStatic;
     let GlobSync: IGlobSyncStatic;