[Feature]: Add drafts to MCP

[nicktar]

Is your feature request related to a problem? Please describe.
The MPC only deals with tasks not drafts and the drafts CLI is incomplete (no edit functionality). For drafts to be first class citizen, we need at least the MCP integration, better both

Describe the solution you'd like
Either additional MCP commands to handle drafts or an extension to the task commands to work with drafts as well. While the first one seems cleaner, the second option seems more in line with how claude code interacts with backlog.md

[MrLesk]

drafts, documents and decisions need a nice improvement. Will work on them in the following weeks