This includes: - not having the general summary or app name anymore hardcoded in the module - moved the functions at module level to be methods inside a class; this is for the system to be able to be "initiated" with the app specific information. - those moved in functions are exactly the same, with some minor structural changes: - `get_full_help` and `get_detailed_help` do not receive the "command groups" - `get_usage_message` now formats `USAGE` passing also the `appname` - `get_full_help` and `get_detailed_help` indents the "general summary" (as the app text doesn't need to be passed indented) **Note** on initiating `Helper`: currently there's no guard on using it before calling its `init`, as I'm not 100% sure the form this will have when both this help texts module and the dispatcher will be in the craft-cli library, but for sure the final form will be more robust. **Note 2**: the PR is too big, but most of it is just moving code around, and zillion changes in the texts because of two functions not receiving command groups anymore, and the need to init the helper before usage.