feat: support JSDoc @event, @fires, @emits, and @listens tags

[divybot]

Adds three new JsDocTag variants to support JSDoc's event-documentation tags so that classes which fire events (e.g. EventTarget subclasses) can be documented with deno doc / on JSR.

Implements:

• @event <name> — declares an event a class can emit
• @fires <name> (alias @emits <name>) — documents which events a method/function fires
• @listens <name> — documents which events a symbol listens for

Names follow the JSDoc convention (e.g. Hurl#snowball, module:hurler~snowball); an optional trailing description is captured into doc.

The new variants are wired into the printer (deno doc terminal output), the tags_same_kind diff helper, and have new serialization and parsing tests.

Example:

/**
 * A connection.
 *
 * @event open - Fired when the connection opens.
 * @event close - Fired when the connection closes.
 */
class Conn extends EventTarget {}

Refs denoland/deno#26697

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}