More descriptive error handling for API calls

[Kenny-Heitritter]

There should be better error responses when using cudaq_solvers.create_molecule and any other code that uses API calls to execute code. When executing the following, the user just gets a blanket error that isn't specific about what went wrong on the pyscf call

from cudaq_solvers import create_molecule

xyz = [('H', (0., 0., 0.)), ('H', (1.0, 0., 0.))]
molecule = create_molecule(xyz, 'sto-3sg', 0, 0)

---------------------------------------------------------------------------
RuntimeError                              Traceback (most recent call last)
Cell In[34], [line 4](vscode-notebook-cell:?execution_count=34&line=4)
      [1](vscode-notebook-cell:?execution_count=34&line=1) from cudaq_solvers import create_molecule
      [3](vscode-notebook-cell:?execution_count=34&line=3) xyz = [('H', (0., 0., 0.)), ('H', (1.0, 0., 0.))]
----> [4](vscode-notebook-cell:?execution_count=34&line=4) molecule = create_molecule(xyz, 'sto-3sg', 0, 0)

RuntimeError: HTTP POST Error - status code 500: : Internal Server Error

when the problem is just that an invalid basis set ('sto-3sg' rather than 'sto-3g') was passed. Similarly, if the xyz is changed such that it is syntactically correct but not what pyscf expects then the error will be the same blanket internal server error.