feat: support serialising Exceptions as JSON strings

mentioned in merge request uis/devops/gsuite/management-functions!38

mentioned in merge request uis/devops/iam/activate-account/account-data-manager!2

mentioned in merge request uis/devops/iam/activate-account/entra-event-handler!26

mentioned in merge request uis/devops/devhub/lookup-gitlab-sync/faas!35

mentioned in merge request uis/devops/iam/ibis/institution-mapping-tool!13

mentioned in merge request uis/devops/infra/terraform/ucam-faas-long!82 (merged)

mentioned in merge request uis/devops/infra/terraform/ucam-faas!130 (merged)

mentioned in merge request uis/devops/gsuite/management-functions!49

mentioned in merge request uis/devops/devhub/lookup-gitlab-sync/faas!57

mentioned in merge request uis/devops/iam/activate-account/account-data-manager!64

mentioned in merge request uis/devops/iam/activate-account/entra-event-handler!47