fix: deadlock and use-after-free in tests (#4981)

* fix: use-after-free in settings

* refactor: put seventv api into a singleton

* chore: add changelog entry

* Add warning for when the 7TV load fails

src/providers/seventv/SeventvEmotes.cpp

@@ -1,5 +1,6 @@
 #include "providers/seventv/SeventvEmotes.hpp"
 
+#include "Application.hpp"
 #include "common/Literals.hpp"
 #include "common/NetworkResult.hpp"
 #include "common/QLogging.hpp"
@@ -214,7 +215,7 @@ void SeventvEmotes::loadGlobalEmotes()
 
     qCDebug(chatterinoSeventv) << "Loading 7TV Global Emotes";
 
-    getSeventvAPI().getEmoteSet(
+    getIApp()->getSeventvAPI()->getEmoteSet(
         u"global"_s,
         [this](const auto &json) {
             QJsonArray parsedEmotes = json["emotes"].toArray();
@@ -243,7 +244,7 @@ void SeventvEmotes::loadChannelEmotes(
     qCDebug(chatterinoSeventv)
         << "Reloading 7TV Channel Emotes" << channelId << manualRefresh;
 
-    getSeventvAPI().getUserByTwitchID(
+    getIApp()->getSeventvAPI()->getUserByTwitchID(
         channelId,
         [callback = std::move(callback), channel, channelId,
          manualRefresh](const auto &json) {
@@ -405,7 +406,7 @@ void SeventvEmotes::getEmoteSet(
 {
     qCDebug(chatterinoSeventv) << "Loading 7TV Emote Set" << emoteSetId;
 
-    getSeventvAPI().getEmoteSet(
+    getIApp()->getSeventvAPI()->getEmoteSet(
         emoteSetId,
         [callback = std::move(successCallback), emoteSetId](const auto &json) {
             auto parsedEmotes = json["emotes"].toArray();