Inter / intra dependency specification and resolution mechanism for marketplace plugins

[grjsrinivas]

Need to have a dependency model for plugins. We should be able to specify dependent plugins for a plugin in a marketplace. The dependencies can be inter or intra marketplace. We need to have a mechanism for specifying and automatically installing dependencies of a plugin.

Claude code has this support already and we need something like this in copilot-cli

https://code.claude.com/docs/en/plugin-dependencies