modules: add command tt modules list

[dmyger]

A command that will produce a list of installed modules.
We walk through the list of modules (from #1014) and try to extract information about each one.

The result should output a list with lines formatted as:

X.Y.Z module_name - description

Where:

• X.Y.Z - is module version
• module_name - command/module name as it will be executed on the command line.
• description - short description of module

This information should be obtained from the manifest.yaml file, if present (#1015).
Otherwise, the main executable file should be run with the appropriate flags to gather information.

If a module has an invalid manifest.yaml or its main entry point does not support responses to requested options, such a module should be ignored and removed from the module list.

Blocked with:

• modules: prepare local modules list #1014 - here we expect a prepared list of potential modules.
• modules: parsing manifest.yaml with minimal set of fields #1015 - parsed information from manifest file