feat(plugins): let a plugin ship translations and read the UI language (#1781)

A package's locales/<tag>.json (English source text -> translation) is applied to the plugin's own manifest titles and labels and to its view data; new ui.locale() (API 1.3) returns the UI language for text the plugin builds itself. Catalogs only ever apply to their own plugin; text without an entry stays English.

Co-authored-by: arnaud-ritti <[email protected]>

plugins/official/string-tools/dist/plugin.wasm.sources

@@ -1 +1 @@
-a6c188aed4fc57cd9955d6b47ef715c52dc3f8c7b69f7d18ea71b3932888710f
+737d1a1eb063a6757e93f0359fc32ab2b624ef8c251a4cba31aa3c36f7587002