Better LLDB debugging visualizations

[AlexandraKemperMS]

Feature Request

Better support when displaying visualizations for debugging, especially for unordered maps, maps, and arrays.

For example, on a physical mac machine compiling with clang++ and using LLDB, this is the current experience:

We should make it easier to see the array size and elements, as well as the items in each unordered map.

There is also limited support for mutexes, with no indicator whether a mutex is locked (in this case, the mutex was named locked):

[AlexandraKemperMS]

When building with g++ on a linux machine and debugging with gdb, this is the equivalent visualization. Not even sizes are shown.