### Summary

Add type hints to `ansible.parsing.dataloader::DataLoader`

### Issue Type

Feature Idea

### Component Name

lib/ansible/parsing/dataloader.py
'''
    The DataLoader class is used to load and parse YAML or JSON content,
    either from a given file name or from a string that was previously
    read in through other means. A Vault password can be specified, and
    any vault-encrypted files will be decrypted.
    Data read from files will also be cached, so the file will never be
    read from disk more than once.
    Usage:
        dl = DataLoader()
        # optionally: dl.set_vault_password('foo')
        ds = dl.load('...')
        ds = dl.load_from_file('/path/to/file')
    '''
    def __init__(self):