Extern: to_xml / from_xml do not always work together well

https://gitlab.com/caosdb/caosdb-pylib/-/issues/89

• this element should be filtered out when storing the xml.
• from_xml should have a flag to be more permissive.
• Followup issues created if necessary

added P3 Statusnext Task labels

changed iteration to Sprint Feb 6, 2023 - Feb 19, 2023

assigned to @daniel

added (B label

set weight to 2

added BugUnconfirmed label

removed Task label

added Statustodo label and removed Statusnext label

added Statusdoing label and removed Statustodo label

removed iteration Sprint Feb 6, 2023 - Feb 19, 2023

changed iteration to Sprint Feb 20, 2023 - Mar 5, 2023

changed iteration to Sprint Mar 6, 2023 - Mar 19, 2023

added Statusnext label and removed Statusdoing label

added Statustodo label and removed Statusnext label

added Statusdoing label and removed Statustodo label

added BugConfirmed label and removed BugUnconfirmed label

added StatusReview label and removed Statusdoing label

removed (B label

removed weight

added Statusnext label and removed StatusReview label