Move mosaic.cal_logs to mosaic.meta.cal_logs

[schlafly]

We moved cal_logs to be in the metadata section of wfi_image, but did not correspondingly move it to be in the metadata of wfi_mosaic. We should make sure that cal_logs is always in the metadata and not at the root level.

[PaulHuwe]

@tddesjardins Do you have an opinion here, vis-a-vis the L3 File Schema Document?

[stscijgbot-rstdms]

This issue is tracked on JIRA as RAD-195.