Chern insulator test case is outdated and poor in performance

[Alphaharrius]

The test case at cherinsulator.jl is using many outdated APIs and requires a revisit in order to improve performance to run renormalization depth test stated by @AdrianHCPo.

[Alphaharrius]

Depth test report

192x192 t_a=-0.9; t_b=-0.1; t_n=-1: 1
192x192 t_a=-0.8; t_b=-0.2; t_n=-1: 2
192x192 t_a=-0.7; t_b=-0.3; t_n=-1: 3
192x192 t_a=-0.6; t_b=-0.4; t_n=-1: 3
192x192 t_a=-0.5; t_b=-0.5; t_n=-1: 6

[Alphaharrius]

Depth test report

192x192 t_a=-0.85; t_b=-0.15; t_n=-1: 1
192x192 t_a=-0.75; t_b=-0.25; t_n=-1: 2
192x192 t_a=-0.65; t_b=-0.35; t_n=-1: 2
192x192 t_a=-0.55; t_b=-0.45; t_n=-1: 2

[Alphaharrius]

The fixed test case is located at test/2D/honeycomb/cherninsulator.jl.