feat: new components

[Droid00000]

Summary

This is my attempt at adding support for the new components that Discord plans to release in the distant future. This introduces the ability to have components besides action rows as top-level components, as well as the ability to nest action rows within other top-level components. Additionally, this PR now includes the Label component that will be coming to modals along with the ability to have TextDisplay components in modals. Some potential points to discuss:

• The example admittedly isn't the best. I'm open to doing something different than what I've current added.
• has_components admittedly isn't the best name for setting the IS_COMPONENTS_V2 (1 << 15) flag.

Added

• Builders for new components:
  Webhooks::View::TextDisplayBuilder
Webhooks::View::SeperatorBuilder
Webhooks::View::FileBuilder
Webhooks::View::MediaGalleryBuilder
Webhooks::View::SectionBuilder
Webhooks::View::ContainerBuilder
Webhooks::Modal::LabelBuilder

• Top-level methods for new components:
  Webhooks::View#text_display
Webhooks::View#seperator
Webhooks::View#file
Webhooks::View#media_gallery
Webhooks::View#section
Webhooks::View#container
Webhooks::Modal#text_display
Webhooks::Modal#label

• Data classes for serializing incoming components:
  Components::TextDisplay
Components::Seperator
Components::File
Components::MediaGallery
Components::Section
Components::Container
Components::Label
Components::FileUpload

has_components KWARG for interaction methods which sets the IS_COMPONENTS_V2 (1 << 15) flag.
Channel#send_message!(**arguments) Same as send_message but with KWARGS and yielded builders.

Changed

There are a couple of internal changes made to Webhooks::View in order to make the new components possible. (Don't worry, full backwards compatibility has been maintained.)

Removal of @rows. Since action rows are no longer the only top-level components, it didn't make sense to have two separate instance variables since it would end up requiring some needless concatenation. E.g.

@rows.map(&:to_h).concact(@components.map(&:to_h))

In its place, I've replaced it with @components as a way to store all top-level components. This required the removal of the attr_reader :rows as well. It was replaced with:

def rows
  @components.select { |component| component.is_a?(RowBuilder) }
end

Fixed

Previously, when passing in an emoji object to RowBuilder#button and SelectMenuBuilder#option, it would yield the following error:

Exception: #<NoMethodError: undefined method `to_h' for an instance of Discordrb::Emoji>

As stated in the error, this is because #to_h wasn't defined anywhere for the emoji object. I've went ahead and defined this method.