feat(tabs): seed default tab layout on first run and v10 wipe

Spawn six themed tabs out of the box instead of one General catch-all:
General (everything), Free Company (FC chat plus FC announcements and
login/logout), Party (Party, CrossParty, Alliance, PvP team plus loot
rolls), Beginner (Novice Network only when ShowNoviceNetwork is on),
Linkshell (all eight regular and cross-world linkshells together) and
Tell Exclusive (TellIncoming/TellOutgoing as a safety-net catch-all in
case Auto-Tell-Tabs misses one).

Tab names live in HellionStrings (EN/DE). The Tabs settings tab gains a
help-text hint above the list recommending one tab per linkshell when
the user is in multiple, since a single combined Linkshell tab gets
noisy fast for active users.

ChatTwo/Ui/SettingsTabs/Tabs.cs

@@ -27,6 +27,9 @@ internal sealed class Tabs : ISettingsTab
     {
         const string addTabPopup = "add-tab-popup";
 
+        ImGuiUtil.HelpText(HellionStrings.Tabs_Presets_Linkshell_Hint);
+        ImGui.Spacing();
+
         if (ImGuiUtil.IconButton(FontAwesomeIcon.Plus, tooltip: Language.Options_Tabs_Add))
             ImGui.OpenPopup(addTabPopup);