4.4.0 Resilient data update

Flag data are now saved on Entity.
This makes flags removable even after server crashes or after the plugin data file have been deleted.
Flags which data can't be saved because of a crash won't be removable by `/fh remove [id]` nor show in the flag list. But they still can be destroyed by player hand.
Most servers won't be affected by this update, but the update will benefit to the server that crashes some time.

Explicitly support 1.21.4.

Explicit support 1.21.3

Fix mangrove fences offset.

This version add explicit support for 1.21.1

# 4.1.0
Banner placed from off hand can no longer remove an other item (#10).
Banner placed with off hand can have alternate mods. Alternates modes allow to place vanilla banner or, banner in switchable block instead of flags (#7).

See https://github.com/HydrolienF/FlagsH/blob/4.1.0/CHANGELOG.md for previous changelog

Support Minecraft 1.21.
FlagsH now require Java 21.

Explicit support for 1.20.5 & 1.20.6.
Work with [1.20 - 1.20.6]

Explicit support for 1.20.3 & 1.20.4.
Still work with 1.20, 1.20.1, 1.20.2.