Add map picker with Featured/All tabs (#3005)

Resolves #2996

## Description:

Replace map selection UI in src/client/SinglePlayerModal.ts and
src/client/HostLobbyModal.ts with the picker (Featured/All tabs + random
map card).

Also, since the html was getting quite long, I extracted the shared
parts into a separate component.

<img width="575" height="592" alt="スクリーンショット 2026-01-23 21 57 03"
src="https://github.com/user-attachments/assets/fc6bfbc3-cb66-452a-b971-436940b0fb99"
/>

<img width="633" height="648" alt="スクリーンショット 2026-01-23 21 57 12"
src="https://github.com/user-attachments/assets/1aa409a1-b801-4a60-8b26-ba20e343d66e"
/>

I separated Map.ts because the display logic looked reusable in other
places, but I’m also open to merging it back if that makes more sense.
If the review prefers it integrated, I can combine them again.

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

aotumuri

resources/lang/en.json

@@ -280,6 +280,8 @@
   },
   "map": {
     "map": "Map",
+    "featured": "Featured",
+    "all": "All",
     "world": "World",
     "giantworldmap": "Giant World Map",
     "europe": "Europe",
@@ -330,6 +332,7 @@
     "amazonriver": "Amazon River"
   },
   "map_categories": {
+    "featured": "Featured",
     "continental": "Continental",
     "regional": "Regional",
     "fantasy": "Other",