ENH: connect tile interpolation AHE backend and frontend

[neutrinoceros]

Of course, the backend doesn't exist yet, but I could do this in 10mins.
ref #302

[neutrinoceros]

blocked by #377

[neutrinoceros]

CI should be green now but

• performance seems abysmal
• using non-square images leads to panics (clearly I'm doing something wrong)
• I needed to set tolerance to extraordinary levels (1.25) to pass tests

All of these are signs that the implementation is buggy and suboptimal but can be addressed as follow ups