fix: Calculation creation and deletion errors solved, set shopping unit preselection if only one is available

[jo-gross]

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Describe your work, what changed

When saving an calculation for the first time, an error was thrown (wrong db query). Thats now solved. If only one unit is available, this one gets preselected at the calculation shopping list unit.

Affected sites (please check during review):

• [ ] [workspaceId]/manage/calculations/[id] - Shopping list unit now preselected if only one is available, delete and create api handling fixed

[jg-semantic-release-bot[bot]]

:tada: This PR is included in version 1.8.2 :tada:

The release is available on:

• GitHub release
• v1.8.2

Your semantic-release bot :package::rocket: