transition to Harmony API from on-prem EGI

[JessicaS11]

NSIDC on-premises subsetting services for ICESat-2 data are currently handled by the EGI system. This system is being sunset in favor of the Harmony subsetter. The timeline for this transition is summer into fall 2024, with the goal to turn off EGI by the end of 2024. icepyx currently submits user data orders to EGI and must therefore be transitioned to use Harmony as well. (On a side note, we also aim to use this transition to set ourselves up for future improved integrations with earthaccess and SlideRule as part of our collective broader efforts to streamline the user experience and the way these tools interact).

Some key notes on how this transition will impact subsetting of ICESat-2 data and icepyx:

• the two-step "search + filter" followed by "order + download with subsetting" workflow will remain unchanged
• the search and filter step to identify granules of interest will still use CMR*
• temporal and spatial subsetting will be available for data product Levels 2-3a; Level 3b data (ATL11, >=ATL14) will have no subsetting options available
• variable subsetting will no longer be available.

*Harmony filters using CMR, so we could combine this into one step, but we still think the search, find services, order/download workflow is best

This parent issue aims to track specific issues required for icepyx to transition to Harmony:

• [harmony] transition ipx.APIformatting to Harmony keys #531
• [harmony] point granules module to Harmony instead of EGI #532
• [harmony] [docs] variables and subsetting #533
• [harmony] components of ipx.query likely impacted by transition from EGI #534
• [harmony] components of ipx.variables and ipx.is2ref likely impacted by transition from EGI #579

Tasks:

• Create final 1.x release (Cut final 1.x release from development branch, marking beginning of breaking changes #599)
• Find low-hanging fruit refactors
• Disable ECS tests as "xfail" (expected fail)
• Replace ECS handling code with Harmony handling code (harmony-py)
• Enable new Harmony integration tests
• [ ]