[lldb] Remove duplicated breakpoint tests
After reverting the deletion of the functionalities/breakpoint tests,
we now have some tests twice in the test/ folder which breaks dotest:
* commands/breakpoint/basic
* functionalities/breakpoint/breakpoint_command
After looking over these tests, I think it makes sense to only
keep the original functionalities/ folder. The commands/breakpoint/basic
test are not exclusively testing the breakpoint command itself, so
they shouldn't be in commands/ in the first place. Note that these
folders have identical contents (beside small adjustments regarding
the Makefile which landed after the restructuring).
llvm-svn: 371734