1.21.5 Bungee chat fixes

[tal5]

This turned out to be a bunch of stuff in one PR, but will try splitting the commits and description at least.

NMSHandler#getVersion calls before initialization

Needed to check the version in FormattedTextHelper's initialization (before NMSHandler), so the version is now checked and stored in a static block so that it's accessible at all times.

Component JSON parsing

ComponentSerializer#parse can no longer be used, as that uses VersionedComponentSerializer#getDefault which returns the 1.16 serializer.

• Adds FormattedTextHelper#parseJson which checks the version and runs it though the proper serializer.

Base vanillaStyleSpigotComponentGSON off of default Bungee serializer

• Adds FormattedTextHelper#getBungeeGson, which returns the Bungee Gson instance.
• vanillaStyleSpigotComponentGSON now uses getBungeeGson + Gson#newBuilder to #disableHtmlEscaping without having to redefine the entire serializer.

Fixes to HoverFormatHelper's workaround

• HoverFormatHelper#tryInitializeItemHoverFix is now called right before FormattedTextHelper.vanillaStyleSpigotComponentGSON is initialized, so that it contains the item hover workarounds.
• tryInitializeItemHoverFix now uses FormattedTextHelper#getBungeeGson.
• tryInitializeItemHoverFix now has different reflection logic for setting a VersionComponentSerializer vs ComponentSerializer.