Add modal file uploads

[freya022]

Pull Request Etiquette

• I have checked the PRs for upcoming features/bug fixes.
• I have read the contributing guidelines.

Changes

• Internal code
• Library interface (affecting end-user code)
• Documentation
• Other: Tests

Closes Issue: NaN

Description

This adds the ability for users to submit files in modals.

Note: The feature will be staff-locked for a while, but you can still submit feedback.

Discord docs: discord/discord-api-docs#7887

Usage

Sending

Modal modal = Modal.create("add-http-cats", "Add an HTTP cat")
        .addComponents(
                Label.of(
                        "HTTP Status Code",
                        TextInput.create("http-status-code", TextInputStyle.SHORT)
                                .setMaxLength(3)
                                .build()
                ),
                Label.of(
                        "File",
                        AttachmentUpload.create("cat-img")
                                .setMaxValues(10)
                                .build()
                )
        )
        .build();

Receiving

Where event is a ModalInteractionEvent:

String statusCode = event.getValue("http-status-code").getAsString();
List<Message.Attachment> cats = event.getValue("cat-img").getAsAttachmentList();

[fa1c0nx]

Haha we were just discussing this and you came out of no where with a solution 🔥