Map downloads on join, faster mod merging, connect cards in the server browser

Map downloader
- A host or dedicated server now tells joiners which Thunderstore package
  its map comes from (the Mods folder name plus manifest.json).
- A player without the map gets a card: icon, name, author, version and
  description, with DOWNLOAD and CANCEL. It works with mouse, keyboard and
  controller.
- Only packages listed as Maps in the ReSkate community are offered, and
  never deprecated, rejected or NSFW ones.
- On yes the package is downloaded, installed into Mods and applied as a
  live mod, then the session loads the map. A small card on the right
  shows the progress, so the player can keep skating.
- The player stays connected while it downloads: the host gives a player
  who says they are fetching the map up to 45 minutes instead of the
  usual load time.
- When the server changes map with the player in it, the card says so.
- Protocol version 47: map package on map_offer and world_state, and a
  "fetching the map" flag on map_request and world_ready.

Joining
- The pause-menu server browser shows a CONNECTING card over the page
  while a join is under way, and a COULDN'T CONNECT card with the reason
  when it does not get in.
- The session and voice tabs no longer show before the player is in.
- Leaving without the map (declined or cancelled download) no longer
  counts towards the failed-join limit, on servers and player hosts.

Input
- A card that asks something holds the game's input until the buttons
  are released.
- Steam's overlay hooks XInput in front of ReSkate and answers the game
  itself, so a controller reached the game behind menus. ReSkate now
  hooks that hook as well.

Mod merging
- Mods are read on several threads, at launch and for live merges. A live
  merge runs below the game's priority.
- The paid-cosmetics check reads the game's files and the mods on several
  threads.
- A live merge reuses the paid-cosmetics verdicts it already has and
  reports its progress and timings.

Launcher
- NSFW mods and their categories are not shown in the mod browser.

Engine/Vfs/https_download.cpp

@@ -20,7 +20,7 @@ struct Internet {
 }
 
 Download get(std::wstring_view url, const std::filesystem::path& destination,
-    std::uint64_t max_bytes, std::uint32_t timeout_seconds, const wchar_t* agent) {
+    std::uint64_t max_bytes, std::uint32_t timeout_seconds, const wchar_t* agent, Watch* watch) {
     Download result;
     const auto fail = [&](DWORD error) { result.error = error; return result; };
     if (url.empty() || url.size() >= 4096 || url.find_first_of(L"\r\n\t #") != std::wstring_view::npos)
@@ -57,18 +57,21 @@ Download get(std::wstring_view url, const std::filesystem::path& destination,
     DWORD length{}; size = sizeof(length);
     if (WinHttpQueryHeaders(request.value, WINHTTP_QUERY_CONTENT_LENGTH | WINHTTP_QUERY_FLAG_NUMBER,
                            nullptr, &length, &size, nullptr) && length > max_bytes) return fail(ERROR_FILE_TOO_LARGE);
+    if (watch) watch->total.store(length), watch->received.store(0);
     Handle output{CreateFileW(destination.c_str(), GENERIC_WRITE, 0, nullptr, CREATE_NEW, FILE_ATTRIBUTE_NORMAL, nullptr)};
     if (output.value == INVALID_HANDLE_VALUE) return fail(GetLastError());
     std::array<char, 65536> buffer{};
     std::uint64_t total{};
     for (;;) {
         if (GetTickCount64() - started >= std::uint64_t{timeout_seconds} * 1000) return fail(ERROR_TIMEOUT);
+        if (watch && watch->cancel.load()) return fail(ERROR_CANCELLED);
         DWORD read{}, written{};
         if (!WinHttpReadData(request.value, buffer.data(), static_cast<DWORD>(buffer.size()), &read)) return fail(GetLastError());
         if (!read) break;
         if (total + read > max_bytes) return fail(ERROR_FILE_TOO_LARGE);
         if (!WriteFile(output.value, buffer.data(), read, &written, nullptr) || written != read) return fail(ERROR_WRITE_FAULT);
         total += read;
+        if (watch) watch->received.store(total);
     }
     if (!total) return fail(ERROR_BAD_LENGTH);
     if (!FlushFileBuffers(output.value)) return fail(GetLastError());