RIA-7508 AIP with witnesses can state witness interpreter req

[DennisHoV1]

JIRA link (if applicable)

https://tools.hmcts.net/jira/browse/RIA-7508

Change description

• Add the new page of selecting witnesses for interpreter support
• Add the necessary unit test

Does this PR introduce a breaking change? (check one with "x")

[ ] Yes
[X] No