Print currently compiling gems. Add verbose attribute to gem command. - #2395

Motivation

Recently in one project I was working on I encountered the following problem when initializing tapioca:

• while compiling gems, the process just halted at some point - I guess it encountered some issues with compiling specific gems
• I had problems with pinpointing exactly WHICH gems Tapioca had problem with - because the pipeline outputs only compiled gems, not ongoing compilations
• This made debugging very hard - finding those problematic gems required me to put debuggers inside library and I don't think that's how it's supposed to work
• Also, it baffled me that --verbose flag didn't change anything in output when running bundle exec tapioca init or bundle exec tapioca gems - I thought it's gonna tell me what's happening in the background or what gems are currently compiled but it looks like this parameter isn't passed to gems command at all
• Eventually, I found those gems that halted tapioca gems compilation process and just excluded them from compilation

Implementation

• I've added @verbose attribute to AbstractGem class which is passed there from cli options
• When @verbose is true, it outputs Currently compiling <gem_name> before compiling gem
• This make it easier to find in the pipeline output which gems are being compiled, but which weren't compiled

Tests

• Two tests for running bundle exec tapioca gems --verbose and bundle exec tapioca gems -V

Example