Merge pull request #336 from john-hill/PLFM-1780

Plfm 1780
Merge pull request #337 from jay-hodgson/develop

SWC-248: Generate appropriate previews for all leaf entities
Merge pull request #340 from jay-hodgson/release-1.21

cherry-pick SWC-248 for release branch
PLFM-1787
Merge pull request #344 from brucehoff/release-1.21

PLFM-1787
PLFM-1787: updates to integration test users
Merge pull request #345 from brucehoff/release-1.21

PLFM-1787: updates to integration test users
Manager chunk file complete
starting on UI
presigned URL
:)
Code review changes
fixed merge conflit of PLFM-1792