SOF-6873: include valence configuration in pseudopotential schema

[pranabdas]

This PR:

1. extends pseudo potential schema to include information about atomic orbitals, e.g., orbital names, occupations
2. added/removed schema fields to match with current web-app implementation
3. updated example/test data

[azech-hqs]

looks good, see comments

[azech-hqs]

As it is fixed, we can also use

"name": {
    "type": "string",
    "description": "name of the data category",
    "enum": ["pseudopotential"]
}

[azech-hqs]

looks good 👍