imports and suggests

[shajoezhu]

see post in #1014 (comment)

1. having many "imports" is not a blocker, we can argue this, hopefully we won't have to.

2. i think we should get some more clarity on the imports as moving forward

3. Actually, only var_labels is used from formatters. We have copied that function to teal.data as col_labels. Perhaps the latter should be used here?
   I think we should drop the use of formatters::var_labels, but promote the use of col_labels (somehow in my memory, var_labels was moved to the teal.widget, as it lives at the root of teal package)

4. I actually wonder about rtables. since tern is in Depends, and rtables are in Depends of tern. so when you load teal.modules.clinical rtables is loaded because of tern being loaded.
   @m7pr , exactly, for rtables and formatters, hence we should be able to move out rtables and formatters to suggests,

5. please correct me if i was wrong, from https://github.com/insightsengineering/teal/blob/main/DESCRIPTION, teal.data was in depends, as teal.code was a depends for teal.data, teal.code should be in suggest for teal right? similarly suggests for tmc.
   in fact, if teal.logger (>= 0.1.1), teal.reporter (>= 0.2.0), teal.widgets (>= 0.4.0), were depends for teal, teal.logger, reporter and widgets, could all become suggests for tmc and tmg, right? things would be easier. right? @averissimo @m7pr @donyunardi @chlebowa

6. shiny should be >= 1.7, and should be moved to suggests, as it was depending on teal, which has depends for shiny >= 1.7.