Preserve bandwidth in multiplication

[jishnub]

This is an attempt to get the following to be banded:

julia> Multiplication(Fun(), NormalizedLegendre())
MultiplicationWrapper : NormalizedLegendre() → NormalizedLegendre()
 0.0      0.57735    ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋅        ⋅
 0.57735  0.0       0.516398   ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋅        ⋅
  ⋅       0.516398  0.0       0.507093   ⋅         ⋅         ⋅         ⋅         ⋅         ⋅        ⋅
  ⋅        ⋅        0.507093  0.0       0.503953   ⋅         ⋅         ⋅         ⋅         ⋅        ⋅
  ⋅        ⋅         ⋅        0.503953  0.0       0.502519   ⋅         ⋅         ⋅         ⋅        ⋅
  ⋅        ⋅         ⋅         ⋅        0.502519  0.0       0.501745   ⋅         ⋅         ⋅        ⋅
  ⋅        ⋅         ⋅         ⋅         ⋅        0.501745  0.0       0.50128    ⋅         ⋅        ⋅
  ⋅        ⋅         ⋅         ⋅         ⋅         ⋅        0.50128   0.0       0.500979   ⋅        ⋅
  ⋅        ⋅         ⋅         ⋅         ⋅         ⋅         ⋅        0.500979  0.0       0.500773  ⋅
  ⋅        ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋅        0.500773  0.0       ⋱
  ⋅        ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋱        ⋱

This also fixes

julia> Multiplication(Fun(), NormalizedJacobi(1,1))
MultiplicationWrapper : NormalizedJacobi(1.0,1.0) → NormalizedJacobi(1.0,1.0)
 0.0       0.447214   ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋅        ⋅
 0.447214  0.0       0.478091   ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋅        ⋅
  ⋅        0.478091  0.0       0.48795    ⋅         ⋅         ⋅         ⋅         ⋅         ⋅        ⋅
  ⋅         ⋅        0.48795   0.0       0.492366   ⋅         ⋅         ⋅         ⋅         ⋅        ⋅
  ⋅         ⋅         ⋅        0.492366  0.0       0.494727   ⋅         ⋅         ⋅         ⋅        ⋅
  ⋅         ⋅         ⋅         ⋅        0.494727  0.0       0.496139   ⋅         ⋅         ⋅        ⋅
  ⋅         ⋅         ⋅         ⋅         ⋅        0.496139  0.0       0.49705    ⋅         ⋅        ⋅
  ⋅         ⋅         ⋅         ⋅         ⋅         ⋅        0.49705   0.0       0.497673   ⋅        ⋅
  ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋅        0.497673  0.0       0.498117  ⋅
  ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋅        0.498117  0.0       ⋱
  ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋅         ⋱        ⋱

Let's see if tests pass with this.

[codecov]

Codecov Report

Base: 67.51% // Head: 67.70% // Increases project coverage by +0.18% 🎉

Coverage data is based on head (85c3970) compared to base (27444b7).
Patch coverage: 100.00% of modified lines in pull request are covered.

❗ Current head 85c3970 differs from pull request most recent head daf2bf2. Consider uploading reports for the commit daf2bf2 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #132      +/-   ##
==========================================
+ Coverage   67.51%   67.70%   +0.18%     
==========================================
  Files          28       28              
  Lines        2475     2477       +2     
==========================================
+ Hits         1671     1677       +6     
+ Misses        804      800       -4     

Impacted Files	Coverage Δ
src/Spaces/PolynomialSpace.jl	88.36% <100.00%> (+1.40%)	⬆️
src/Spaces/Jacobi/Jacobi.jl	63.36% <0.00%> (+0.99%)	⬆️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.