Refactor names (#31405)

This PR only does "renaming":

* `Route` should be `Router` (and chi router is also called "router")
* `Params` should be `PathParam` (to distingush it from URL query param, and to match `FormString`)
* Use lower case for private functions to avoid exposing or abusing

routers/api/v1/repo/tree.go

@@ -56,7 +56,7 @@ func GetTree(ctx *context.APIContext) {
 	//   "404":
 	//     "$ref": "#/responses/notFound"
 
-	sha := ctx.Params(":sha")
+	sha := ctx.PathParam(":sha")
 	if len(sha) == 0 {
 		ctx.Error(http.StatusBadRequest, "", "sha not provided")
 		return