feat: unified errors and error codes

[imhoffd]

This unifies the base class of Capacitor exceptions to a new Capacitor.Exception class, allowing the following:

err instanceof Capacitor.Exception; // true

Additionally, the .unimplemented()/.unavailable() helpers on iOS, Android, and Web can now accept a message argument and use the new exception codes to allow the following:

e.code === ExceptionCode.Unimplemented; // true
e.code === ExceptionCode.Unavailable; // false

These codes make it easier for people to check what went wrong with Plugin API calls.

Because of the new availability of UNAVAILABLE on iOS and Web, it makes sense to remove UNSUPPORTED_BROWSER and use unavailable instead. Usage example:

--- a/haptics/src/web.ts
+++ b/haptics/src/web.ts
@@ -1,4 +1,4 @@
-import { UnsupportedBrowserException, WebPlugin } from '@capacitor/core';
+import { WebPlugin } from '@capacitor/core';

 import type {
   HapticsPlugin,
@@ -70,9 +70,7 @@ export class HapticsWeb extends WebPlugin implements HapticsPlugin {
     if (navigator.vibrate) {
       navigator.vibrate(pattern);
     } else {
-      throw new UnsupportedBrowserException(
-        'Browser does not support the vibrate API',
-      );
+      throw this.unavailable('Browser does not support the vibrate API');
     }
   }
 }

closes #3670

[jcesarmobile]

just two minor comments, other than that looks and works good.

[jcesarmobile]

looks good