[DAR-1657][External] Introduce by-passable warning when an import will overwrite annotations

[JBWilkie]

Problem

When importing annotations to a dataset item with existing annotations, unless append is set to True, the current annotations will be overwritten. Several users have been inconvenienced by the lack of warning when doing this

Solution

Introduce a by-passable warning that presents users with the potential impact of their import if any item targeted in the import has annotations. The warning is not displayed if:

• No item targeted by the import has annotations, or:
• The --overwrite option is set to True when executing the import

Changelog

Introduced a by-passable warning when performing an annotation import that would overwrite existing annotations

[linear]

DAR-1657 Create confirmation dialogue before overwritting annotations