fix: have LargeZNIrrep actually have unknown size of sector values

[borisdevos]

LargeZNIrrep wasn't actually avoiding the NTuple storage method in graded spaces. Tracked it down to some annoying Julia dispatch.

Before:

julia> I = ZNIrrep{200};

julia> II = LargeZNIrrep{200};

julia> Vect[I]
ZNSpace{200} (alias for GradedSpace{ZNIrrep{200}, NTuple{200, Int64}})

julia> Vect[II]
GradedSpace{LargeZNIrrep{200}, NTuple{200, Int64}}

After:

julia> Vect[II]
GradedSpace{LargeZNIrrep{200}, TensorKit.SortedVectorDict{LargeZNIrrep{200}, Int64}}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

Files with missing lines	Coverage Δ
src/irreps/znirrep.jl	93.54% <100.00%> (+3.22%)	⬆️

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