Message Rework (#2187)* Split send and edit requests* Introduces new builders and interfaces* Add support for file descriptions* Replace file sending methods with FileUpload variants* Delete AttachmentOption* Add SplitUtil* Add MessageCreateRequest#setSuppressEmbeds* Downgrade gateway api to version 9 until deadline* Add Message#getComponents* Improve handling of FileUpload#close* Add Request#cleanup to handle cancelled request cleanup* Rename WebhookMessageAction to WebhookMessageCreateAction* Add FileUpload#setName* Update note for resource handling (commit: e111d55)