chore: rewrite user-facing JS messages in Projects module

Conservative cleanup of frappe.throw/msgprint messages per the message style
guide; meaning, severity, and .format() arguments are unchanged:

- index bare {} placeholders as {0}/{1}/... so translators can reorder
- move f-strings / .format() / concatenation out of _() (they break gettext
  extraction and never translate)
- wrap translatable dynamic values (DocType/Select labels) in _()
- fix grammar and colloquialisms
- drop no-op _() wrapping runtime-built strings

Part of #53976.

erpnext/projects/doctype/project/project.js

@@ -137,7 +137,7 @@ frappe.ui.form.on("Project", {
 			freeze_message: __("Updating Costing and Billing fields against this Project..."),
 			callback: function (r) {
 				if (r && !r.exc) {
-					frappe.msgprint(__("Costing and Billing fields has been updated"));
+					frappe.msgprint(__("Costing and Billing fields have been updated"));
 					frm.refresh();
 				}
 			},