[JUJU-299] Store unit CharmURL as a string reference#13546

Merged

jujubot merged 2 commits intojuju:2.9from manadart:2.9-unit-charm-url

Dec 10, 2021

+258-172

Commits on Dec 6, 2021

Updates unit BSON document to store CharmURL as a string pointer instead
manadart
committed

Commits on Dec 10, 2021

Replaces the only usage of untiDoc in upgrades with the document as it
manadart
committed