Miscellaneous endpoint coverage (login-banner, smtp PATCH, fs performance, presets/workload, …)

[juemerson-at-purestorage]

No shared theme; pick up opportunistically. Roadmap priority P5-14.

• login-banner GET (2.0)
• smtp-servers PATCH (2.0)
• file-systems/performance GET (2.0)
• policies/file-system-snapshots DELETE (2.0)
• policies/members GET (2.0)
• file-systems/policies-all GET (2.3)
• presets/workload PUT (2.23)
• resiliency-groups/members GET (2.23)

Blocked on: nothing.
Owner: TBD.