Refactor conditional logic in partition/auto.py to use a hash map instead of conditional statements

[MthwRobinson]

The goal of this issue is to refactor conditional logic in partition/auto.py to use a hash map instead of conditional statements. #591 implemented a similar refactor for file_utils/filetype.py.

[qued]

So like a map from filetype to the function that processes that type?

[MthwRobinson]

Yeah something like:

PARTITION_MAP = {
    FileType.EML: partial(partition_email(encoding=encoding))

}

...

partition_func = PARTITION_MAP.get(FileType.EML)
elements = partition_func(filename=filename, file=file)