[lldb][progress] Add progress manager class (#81319)

Per discussions from https://github.com/llvm/llvm-project/pull/81026, it
was decided that having a class that manages a map of progress reports
would be beneficial in order to categorize them. This class is a part of
the overall `Progress` class and utilizes a map that keeps a count of
how many times a progress report category has been sent. This would be
used with the new debugger broadcast bit added in
https://github.com/llvm/llvm-project/pull/81169 so that a user listening
with that bit will receive grouped progress reports.