This PR introduces new definitions for types in Tribol. The changes are as follows:

• Remove tribol::integer in favor of int, or other C++ fundamental types as dictated by the specific variable (e.g. unsigned short might make more sense for a variable that represents spatial dimension)
• Define tribol::IndexT as axom::IndexType for indexing into axom types (e.g. axom::Array). Note the use of tribol::IndexT still needs to be checked in source files. This will be done in future PRs.
• Rename tribol::real as tribol::RealT and ensure proper usage throughout source files. tribol::RealT is defined as a double; if the user attempts to map it to float by defining TRIBOL_USE_SINGLE_PRECISION, an error will occur since Tribol has not been tested with single precision.
• Rename tribol::containerArray as tribol::ArrayT and define it as an axom::Array (with template arguments) instead of std::vector
• Rename tribol::CommType to tribol::CommT to be consistent with other Tribol type names

Note, this PR does not address types in redecomp or in the Fortran/C interface.