Add: admin menu for companies in multiplayer games

You can now easily do:
- a password reset (unlock)
- remove an empty company (reset company)

src/company_cmd.cpp

@@ -571,7 +571,6 @@ Company *DoStartupNewCompany(bool is_ai, CompanyID company = INVALID_COMPANY)
 	GeneratePresidentName(c);
 
 	SetWindowDirty(WC_GRAPH_LEGEND, 0);
-	InvalidateWindowClassesData(WC_CLIENT_LIST_POPUP);
 	InvalidateWindowData(WC_CLIENT_LIST, 0);
 	InvalidateWindowData(WC_LINKGRAPH_LEGEND, 0);
 	BuildOwnerLegend();
@@ -909,6 +908,8 @@ CommandCost CmdCompanyCtrl(TileIndex tile, DoCommandFlag flags, uint32 p1, uint3
 			CompanyAdminRemove(c_index, (CompanyRemoveReason)reason);
 
 			if (StoryPage::GetNumItems() == 0 || Goal::GetNumItems() == 0) InvalidateWindowData(WC_MAIN_TOOLBAR, 0);
+			InvalidateWindowData(WC_CLIENT_LIST, 0);
+
 			break;
 		}