Make "moderation mode" setting persist

[dnsge]

Pull request checklist:

CHANGELOG.md was updated, if applicable
(fixes bug in unversioned change)

Description

Fixes a small bug introduced in #1964. "Moderation mode" would be written to the settings file but wouldn't be loaded.

Closes #2032

[pajlada]

Thanks!

[fourtf]

Where in the code does it get loaded?

[dnsge]

The moderationMode value is read from the split descriptor in these two places:

chatterino2/src/widgets/splits/SplitContainer.cpp

Line 718 in fdb2444

split->setModerationMode(splitNode.moderationMode_);

chatterino2/src/widgets/splits/SplitContainer.cpp

Line 750 in fdb2444

split->setModerationMode(splitNode.moderationMode_);

The issue was that splitNode.moderationMode_ wasn't being read from the JSON file and instead defaulted to false.

chatterino2/src/common/WindowDescriptors.hpp

Lines 37 to 38 in fdb2444

	// Whether "Moderation Mode" (the sword icon) is enabled in this split or not
	bool moderationMode_{false};