Add HDF5IO tests for add_read PR

[oruebel]

This PR targets #85 to complete open ToDo items to add unit tests.

Add unit tests for public HDF5IO-specific functions (i.e., not inherited from BaseIO)

• HDF5IO::getH5ObjectType
• HDF5IO::getNativeType
• HDF5IO::getH5Type

Add unit tests for new publicHDF5IO functions (which are core functions new inBaseIO). While some of these are partially covered by the DEFINE_FIELDS read tests, it will be useful to more fully test these separately

• HDF5IO::readDataset (incl. with start, count, stride, and block parameters set). This is to test that reading subsets of larger arrays works as expected.
• HDF5IO::open(FileMode mode) test that file modes are being set correctly
• HDF5IO::readAttribute
• HDF5IO::getStorageObjectType
• HDF5IO::getGroupObjects
• HDF5IO::attributeExists
• HDF5IO::objectExists

New TODO items identified in unit tests:

• Update HDF5IO::readDataset to cover all numeric types in BaseDataType
• Debug reading of strings and update theTEST_CASE("HDF5IO; read dataset", "[hdf5io]") and TEST_CASE("HDF5IO; read dataset subset", "[hdf5io]").
  • Fixed writing of fixed length strings (the data type was not being set correctly)
  • Fixed reading of fixed length strings
  • Fixed writing of variable length strings via HDF5RecordingData::writeDataBlock
  • Fixed reading of variable length string datasets
  • Fixed reading of empty string datasets

[oruebel]

@stephprince there is still an issue with reading strings, but otherwise this PR is ready for you to take a look at.

[oruebel]

I have confirmed now that the fixed length string dataset is being written correctly. However, reading of fixed length string data still fails. I have not investigated the issues with variable length strings yet.

[oruebel]

Ok, fixed length strings seem to work now for both write and read. Next up, variable length strings.

[oruebel]

@stephprince I've now fixed the writing/reading of fixed and variable length strings. This PR is ready for you to take a look at. I think the other TODO items for #85 are probably best done in additional PRs, otherwise this PR will become to large.

The last remaining issue for this PR is to fix the address sanitizer test. It looks like the sanitizer doesn't like something about the changes in HDF5RecordingData::writeDataBlock . Getting string datasets to work for write/read is a bit tricky.