The changes to PneumaticsBase.cpp were to fix errors like the following
from enum classes not being formattable:
```
allwpilib/wpilibc/src/main/native/cpp/PneumaticsBase.cpp:36:9: required from here
allwpilib/wpiutil/src/main/native/fmtlib/include/fmt/core.h:2672:12: error: use of deleted function ‘fmt::v8::detail::fallback_formatter<T, Char, Enable>::fallback_formatter() [with T = frc::PneumaticsModuleType; Char = char; Enable = void]’
2672 | auto f = conditional_t<has_formatter<mapped_type, context>::value,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2673 | formatter<mapped_type, char_type>,
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2674 | fallback_formatter<T, char_type>>();
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```
Having PCM as a singleton is a problem, as multiple things need to use it, and that gets really ugly. This changes PCM's to be a reference counted object, that can be passed around and constructed from multiple places.
In Java, this is using a map to hold a data store with a ref count, and allocating new objects any time a duplicate is requested.
In C++, this uses a trick constructor to store a PCM instance in the data store itself. This instance can then be passed to base objects using std::shared_ptr's aliasing constructor, which means constructing a solenoid from a PCM is not allocating after the 1st one.
This did require removing sendable from PCM. A compressor class was added back in to act as sendable for the PCM.
After this change is finished, the only change RobotBuilder and Team Code would require is passing a module type to solenoid constructors.
Co-authored-by: sciencewhiz <sciencewhiz@users.noreply.github.com>
