Ignore Tickish Breakpoints when serialising Core into interface files

This fixes Trac #8333

Thanks to 'klao', who identified the cause and provided the patch
Refactor AMP warnings a bit

There was a bit of clutter (tryTc stuff) caused by the
fact that tcLookupImported didn't return a MaybeErr.
Now it does.  That finishes up Trac #8004.
Kill Type.isKindTy in favour of Kind.isKind (same code)
Nuke tc-trace that makes the typechecker loop

The trace was being over-eager, which disturbs the typecheckers
careful knot-tying
Improve error message for deriving polykinded Typeable (Trac #7800)

Thanks to Krzysztof Gogolewski (monoidal) for the first draft of this patch
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