message(): Control indentation via `CMAKE_MESSAGE_INDENT`
Having a list of strings instead of a numeric variable has the following advantages:
- no need to do
math()
which is error-prone and hard(er) to read - easy to
APPEND
/POP_BACK
for unscoped contexts (out of any function) - make it possible to have custom paddings -- i.e. w/ different lengths or having non-space strings (like
*
)