Move methods of creating multiple manifests from API to manifest generator

[linglp]

Context

Move some methods that were previously in routes.py to ManifestGenerator without going through refactor. Related to FDS-1350.

Changelog

• Move create_single_manifest function that was previously nested under get_manifest_route in routes.py to an independent function in ManifestGenerator
• Move the logic of previously generating multiple manifests that was previously under get_manifest_route to ManifestGenerator.
• Now, regardless the number of data_type and dataset_ids, the API could just call mg.create_manifests to generate multiple or single manifests
• Added type hinting to create_single_manifest and create_manifests and reorganize some of the parameters

Test

1. Generate new Patient manifest as a google sheet

• Example data model
• data_type: Patient
• output_format: google_sheet
  Got expected output: a new patient manifest gets generated. The return contains one google sheet link.

2. Generate multiple new manifests as google sheets

• Example data model
• data_type: Patient
• output_format: google_sheet
  Got expected output: three manifests gets generated. The return contains three google sheet link.

3. Generate an existing manifest as a google sheet

• Example data model
• data_type: Patient
• dataset_id: syn51547836
• output_format: google_sheet
  Got expected output: one manifest gets generated. The return contains one google sheet link: https://docs.google.com/spreadsheets/d/1UECgUSxinXj2lJ02f0GASw0rRmSs-nHiJnAdBJMJBqc/edit#gid=0

4. Generate an existing manifest as an Excel sheet

• Example data model
• data_type: Patient
• dataset_id: syn51547836
• output_format: excel
  Got expected output: An excel spreadsheet gets returned and then content of the manifest is the same as the one above

5. Generate multiple existing manifests as google sheets

• Example data model
• data_type: Patient, Biospecimen
• dataset_id: syn51547836, syn51547837
• asset_view: syn51547844
• output_format: google_sheet
  Got expected output: Two google sheet urls got returned. (See here and here)

6. Make sure use_annotations parameter is working

• Example data model
• use_annotations: true
• asset_view: syn51707141
• dataset_id: syn25614635
• data_type: BulkRNA-seqAssay
• output_format: google_sheet
  Got expected output: https://docs.google.com/spreadsheets/d/1o0ZL86TzAbcU3pT8c09pp6Uv5j5jlTJB68BU855URP0/edit#gid=0

7. Ran all the tests in test_api.py related to generating a manifest

[mialy-defelice]

@andrewelamb do you think this PR is ready?

[andrewelamb]

@mialy-defelice I have some unresolved comments from last week.