feat: add notifier for external plugins

[iProdigy]

Closes #665

[pajlada]

Overall looks great, great PR number too 😈 - just some questions on the API

[iProdigy]

sample notif

[adamk33n3r]

great PR number too 😈

I thought about this too haha. Looking forward to this. Will be cool!

[iProdigy]

using latest icon

[pajlada]

Other than the mini nits, this looks good to me 👍

[Mm2PL]

It works via the RuneLite Shell from debug mode.

import net.runelite.client.eventbus.EventBus;
var eventBus = inject(EventBus.class);

log.info("Hello {}", client.getGameState());

Map<String, Object> data = new HashMap<>();
data.put("sourcePlugin", "RuneLite Shell");
data.put("text", "This is the primary content within the webhook. %USERNAME% will automatically be replaced with the player name and you can define your own template replacements like %XYZ%");
data.put("replacements", Map.of());
//Map.of("%XYZ%", AReplacement.ofText("sample replacement")));
data.put("title", "An optional embed title for your notification");
data.put("imageRequested", true);
data.put("fields", List.of());
data.put("metadata", Map.of("custom key", "custom value"));
data.put("urls", null);
//data.put("urls", Arrays.asList(okhttp3.HttpUrl.parse("http://localhost:3000/dink")));
PluginMessage dinkRequest = new PluginMessage("dink", "notify", data);

eventBus.post(dinkRequest);

Just a question