[feature] add support for passing directory containing multiple manifest files

[mcarter-cyber]

Is this Feature/Enhancement related to an Existing Problem? If so, please describe:

• Splitting manifest content into multiple files helps with readability and maintainability of the manifest repository. Multiple manifest files can be passed to the hauler store sync command, but this can quickly become unwieldy.

Describe Proposed Solution(s):

• Addition of a hauler store sync flag that accepts a directory containing hauler manifest files, with the potential of searching recursively.

Describe Possible Alternatives:

• None at this time.

Additional Context:

• N/A