feat: Add missing application fields (event webhooks, flags_new)

[sentry]

Description

This PR addresses the issue of missing properties in the TransportApplication model when deserializing Discord API responses for applications. Discord's /applications/@me endpoint now returns additional fields that were not previously mapped, leading to warnings in the logs.

Specifically, this PR:

• Introduces a new enum ApplicationEventWebhooksStatus to represent the status of event webhooks.
• Adds event_webhooks_url, event_webhooks_status, and event_webhooks_types properties to TransportApplication.cs with appropriate [JsonProperty] attributes.
• Surfaces these new event webhook properties on the DiscordApplication entity.
• Confirms that flags_new is already correctly mapped in TransportApplication.cs (though it was missing in older releases, it's present on main).

These changes ensure that DisCatSharp correctly deserializes the full application payload from Discord, preventing warnings about unhandled properties and making the new data accessible to developers.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Test A
• Test B

Test Configuration:

• Firmware version:
• Hardware:
• Toolchain:
• SDK:

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules

@Aiko-IT-Systems/discatsharp-reviewer

Fixes DISCATSHARP-2HG