SVM: Determine cause of GAIA alignment failures for WFC3/UVIS

[stscijgbot-hstdp]

Issue HLA-463 was created on JIRA by Warren Hack:

Despite having enough GAIA sources in the field, only a smaller than expected fraction of WFC3/UVIS fields actually get aligned to GAIA. Explanations for these failures should be determined, and if possible, addressed in the code and/or parameter settings for alignment to GAIA.