`measure_function.isFinite` override `fintype.isFinite`

[CohenCyril]

analysis/theories/measure_theory/measure_function.v

Lines 1403 to 1404 in e043b2a

	HB.mixin Record isFinite d (T : semiRingOfSetsType d) (R : numDomainType)
	(k : set T -> \bar R) := { fin_num_measure : fin_num_fun k }.

We must rename this mixin otherwise declaring a type finite in a environment with all_analysis loaded leads to an error.