Add support for Npc Dialogues

[TotallyNoCallum]

This PR is my attempt at adding NPC Dialogues as NpcForms to Cumulus (Would close #4 )
This will also require changes in Geyser (GeyserMC/Geyser#6690), Floodgate works with this without any changes (besides bumping cumulus to 2.0.0 there)

Code for this ^ image

(armorStand is an ArmorStand in Paper's api)

FloodgateApi.getInstance().getPlayer(p.getUniqueId()).sendForm(
                                      NpcForm.builder()
                                              .title("Title")
                                              .content("Content")
                                              .entity(armorStand.getUniqueId())
                                              .button("button 1")
                                              .button("button 2")
                                              .button("button 3")
                                              .validResultHandler(response -> {
                                                  p.sendRichMessage("You clicked button " + (response.clickedButtonId() + 1));
                                                  //run on main thread
                                                  new BukkitRunnable() {
                                                      public void run() {
                                                          armorStand.remove();
                                                          cancel();
                                                      }
                                                  }.runTaskTimer(GeyserNpcDialogTest.getPlugin(GeyserNpcDialogTest.class), 1, 1);
                                              })
                                              .build()
                              );

Buttons are also entirely optional (which also means validResultHandler intentionally isn't usable in this case)

Code for this ^ image

(fish is a Silverfish in Paper's api)

FloodgateApi.getInstance().getPlayer(p.getUniqueId()).sendForm(
                                      NpcForm.builder()
                                              .title("Crazy?")
                                              .content("Crazy? I was crazy once, They locked me in a room, a rubber room, a rubber room of rats, and rats make me crazy")
                                              .entity(fish.getUniqueId())
                                              .entityOffset(-7, 0, 0)
                                              .closedOrInvalidResultHandler(response -> {
                                                  //run on main thread
                                                  new BukkitRunnable() {
                                                      public void run() {
                                                          fish.remove();
                                                          cancel();
                                                      }
                                                  }.runTaskTimer(GeyserNpcDialogTest.getPlugin(GeyserNpcDialogTest.class), 1, 1);
                                              })
                                              .build()
                              );

The limitations of this are that Npcforms can only have 6 buttons (from my testing, adding more causes all the buttons to vanish), and Player/Mannequin entities specifically dont show up in the entity portrait (I believe due to client limitations)

I decided on making a .button() method instead of .button1(), .button2(), .button3(), etc (like how ModalForm has it), as working with 6 button string would get messy imo. Speaking of, I made the buttons Strings instead of ButtonComponents since they cant have images, and also how the json is layed out in the dialogue packet in Geyser/actionJson. Calling .button() when theres already 6 buttons will be silently ignored

For the npc_data and actionJson variables in NpcFormImpl.java, I used rtm516/Geyser@95cb8a4 as a reference