macro definition likely to cause conflict

[jacobmerson]

pcms/src/pcms/interpolator/linear_interpolant.hpp

Line 7 in b747946

#define MAX_DIM 10

This macro specifying the maximum dimension of the interpolation is problematic for a couple of reasons:

1. the name is likely to conflict with other codes/applications
2. there are times when compile-time sizes may be necessary like this. If we are hardcoding them, we should prefer a constexpr variable as it is less likely to conflict if we are going to hard-code.