Standardize Sofast measurement HDF format

[braden6521]

Standardized the format which a Sofast measurement is saved in an HDF5 file by making the following edits. This will help reduce future confusion by standardizing all Sofast measurement files.

• Updated the associated Sofast measurement classes to save in and load from only the current save format.
• Updated all Sofast HDF5 measurement files in the unit test data.
• Updated missing/incorrect documentation throughout Sofast measurement classes.

[bbean23]

Thank you for standardizing this interface! Please either:

A) Update the documentation to reflect my comment and re-submit for approval.
B) Merge as-is, but create a follow-up ticket to clarify the documentation.

[bbean23]

It is unclear whether the intention is for the prefix parameter to be a folder (ending in '/') or if it is just supposed to be the beginning of the name. I'd suggest updating the documentation and/or parameter name with the intended usage. Maybe something like:

def save_to_hdf(self, file: str, prefix: str = '') -> None:
    """Saves data to given file. Data is stored as: PREFIX + Folder/Field_1
    Parameters
    ----------
    file : str
        HDF file to save to
    prefix : str, optional
        Prefix to prepend to the folder path within the HDF file. Suggested use
        is as a prefix to the folder name such as "202407_BCS_", so that folders
        can still be easily machine identified. Note that folders must be
        separated by "/", so if prefix is a folder name, then it should end in
        "/". Default is empty string ''.
    """

Note also that I changed "append" to "prepend".