Fix HangerResonator

[iqmtestd]

It uses the more efficient WaveguideCoplanar and thus also avoids recursive element usage (disallowed by KLayout) when insertend in WaveguideComposite.

Fix #69

[github-actions[bot]]

Test results

       5 files  ±0         5 suites  ±0   3m 30s :stopwatch: -18s    333 tests ±0     332 :heavy_check_mark: ±0  1 :zzz: ±0  0 :x: ±0  1 665 runs  ±0  1 660 :heavy_check_mark: ±0  5 :zzz: ±0  0 :x: ±0 

Results for commit ef928b26. ± Comparison against base commit a7671059.