Store arrays in model parameters as arrays and not as strings to simplify code.

[GernotMaier]

Arrays are stored in the model parameters typically as strings, similar to the way sim_telarray is doing it.

Example:

{
    "schema_version": "0.2.0",
    "parameter": "telescope_transmission",
    "instrument": "LSTN-design",
    "site": "North",
    "parameter_version": "1.0.0",
    "unique_id": null,
    "value": "0.969 0.0 0.0 0.0 0.0 0.0",
    "unit": "null, null, null, null, null, null",
    "type": "float64",
    "file": false
}

This requires multiple string-to-list and list-to-string conversion in the code (general.convert_string_to_list and gen.convert_list_to_string.). I suggest that we store arrays as arrays (meaning above would be stored as [0.969, 0.0, 0.0, 0.0, 0.0, 0.0]) and we do only once a conversion to strings: when writing the sim_telarray configuration files.

[GernotMaier]

A first step to address this issue is to convert all string-like arrays in the model repository / database, see gitlab merge request.