TST: Improve coverage of dwt
TST: Improve coverage of dwt

Test with partial complex coefficients, and with Wavelet input to
dwt_coeff_len

PyWavelets/pywt,michelp/pywt,grlee77/pywt,rgommers/pywt,eriol/pywt,eriol/pywt,kwohlfahrt/pywt,eriol/pywt,michelp/pywt,rgommers/pywt,rgommers/pywt,kwohlfahrt/pywt,PyWavelets/pywt,rgommers/pywt,michelp/pywt,kwohlfahrt/pywt,grlee77/pywt