module linting should ensure that the modules are either `tool` or `tool/subtool`

[famosab]

Description of feature

See this PR for example: nf-core/modules#11285

They added modkit/extract/full. Something like this should be easily catched and lead to a failed linting with a hint to the module specifications.

https://nf-co.re/docs/specifications/components/modules/general#module-granularity