Pull out Vector personal tools styles into skinStyle

Most of the skin styles are no longer needed for modern
Vector. This refactors them so that they only apply
to legacy vector, reducing the overrides needed inside
Vector.

Depends-On: I1edee874a42b070bc319648496ae80a01b6365fb
Bug: T289630
Change-Id: Ic5ab5172d881c48caae6bb3691ccc95515dcdcdb

extension.json

@@ -300,7 +300,18 @@
 			"targets": [ "desktop", "mobile" ],
 			"styles": "css/ext.uls.pt.less",
 			"skinStyles": {
-				"monobook": "css/ext.uls.pt-monobook.less"
+				"default": [
+					"css/ext.uls.pt.less",
+					"css/ext.uls.pt-default.less"
+				],
+				"vector": [
+					"css/ext.uls.pt-vector.less"
+				],
+				"monobook": [
+					"css/ext.uls.pt.less",
+					"css/ext.uls.pt-default.less",
+					"css/ext.uls.pt-monobook.less"
+				]
 			}
 		},
 		"ext.uls.setlang": {