`download` level 2 products should error when a burst ID is missing from ASF

[scottstanie]

In [3]: download_cslc_static_layers(['T147-314895-IW1', 't147_314896_iw3'], output_dir='te1')
Out[3]: [PosixPath('te1/OPERA_L2_CSLC-S1-STATIC_T147-314895-IW1_20140403_S1A_v1.0.h5')]