Turn sparse DelayedArray support back on

[lazappi]

Reminder to do this now that grimbough/rhdf5#79 has been fixed.

To do:

• Remove the is_sparse() check
• Update tests
• Remove code coverage guards

[lazappi]

Tried doing this quickly, writing worked ok but it broke reading.

[LTLA]

Will look at this later. I think we need to flip a few flags in h5writeAttributes to properly save it as a UTF-8 string scalar. What was the error?

[lazappi]

I probably should have copied it here but from memory, something along the lines of X is not a valid path.

[lazappi]

Just checked where this is at. If you remove the is_sparse() check in this line:

zellkonverter/R/write.R

Line 91 in e47c845

if (is(ass_list[[a]], "DelayedMatrix") && !is_sparse(ass_list[[a]])) {

Then writing works fine but reading the output file fails with this error:

Error in py_call_impl(callable, call_args$unnamed, call_args$named) : 
  TypeError: unhashable type: 'list'
Error raised while reading key 'X' of <class 'h5py._hl.group.Group'> from /

And this error on the Python side:

TypeError: unhashable type: 'list'
Error raised while reading key 'X' of <class 'h5py._hl.group.Group'> from /