Ia 5504 api add a way to retrieve all listed missions for a planning

[hugo093]

What problem is this PR solving?

Explain here in one sentence.

Related JIRA tickets

IA-XXX, WC2-XXX, POLIO-XXX, POLIOPM-XXX SLEEP-XXX, SNT-XXX, CONSOLE-XXX

Changes

Explain the changes that were made.

The idea is not to list exhaustively all the changes made (GitHub already provides a full diff), but to help the reviewers better understand:

• which specific file changes go together, e.g: when creating a table in the front-end, there usually is a config file that goes with it
• the reasoning behind some changes, e.g: deleted files because they are now redundant
• the behaviour to expect, e.g: tooltip has purple background color because the client likes it so, changed a key in the API response to be consistent with other endpoints

How to test

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If a specific config is required explain it here: dataset, account, profile, etc.

Print screen / video

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Notes

Things that the reviewers should know:

• known bugs that are out of the scope of the PR
• other trade-offs that were made
• does the PR depends on a PR in bluesquare-components?
• should the PR be merged into another PR?

Doc

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