LibVT: Rename escape$m to SGR (Select Graphic Rendition)

Author: https://github.com/linusg
Commit: dcb5bf9e50
Pull-request: https://github.com/SerenityOS/serenity/pull/1137
Reviewed-by: https://github.com/awesomekling

Libraries/LibVT/Terminal.h

@@ -161,7 +161,7 @@ private:
     void escape$X(const ParamVector&);
     void escape$b(const ParamVector&);
     void escape$d(const ParamVector&);
-    void escape$m(const ParamVector&);
+    void SGR(const ParamVector&);
     void escape$s(const ParamVector&);
     void escape$u(const ParamVector&);
     void escape$t(const ParamVector&);