This is an API for looking up a Pose3d from a tag id, and includes functionality to load that map from a JSON file.
This also adds JSON support to Pose3d, Rotation3d. Translation3d, and Quaternion.
Co-authored-by: Tyler Veness <calcmogul@gmail.com>
Co-authored-by: AMereBagatelle <themerebagatelle@gmail.com>
Now, implicit narrowing conversions are only used with wpi::Now(). This
also fixes clang-tidy warnings about C-style casts. For example:
```
== clang-tidy /__w/allwpilib/allwpilib/wpilibNewCommands/src/main/native/include/frc2/command/SwerveControllerCommand.inc ==
/__w/allwpilib/allwpilib/wpilibNewCommands/src/main/native/include/frc2/command/SwerveControllerCommand.inc:95:18: warning: C-style casts are discouraged; use static_cast/const_cast/reinterpret_cast [google-readability-casting]
auto curTime = units::second_t(m_timer.Get());
^
```
In that case at least, the cast was removed entirely since Get() already
returns a units::second_t.
