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/notes.go

@@ -52,7 +52,7 @@ func GetNote(ctx *context.APIContext) {
 	//   "404":
 	//     "$ref": "#/responses/notFound"
 
-	sha := ctx.Params(":sha")
+	sha := ctx.PathParam(":sha")
 	if !git.IsValidRefPattern(sha) {
 		ctx.Error(http.StatusUnprocessableEntity, "no valid ref or sha", fmt.Sprintf("no valid ref or sha: %s", sha))
 		return