CIV-14413 Dashboard Notify hearing scheduled

[karthick-mohanasundaram-HMCTS]

Before creating a pull request make sure that:

• [x] commit messages are meaningful and follow good commit message guidelines
• [x] README and other documentation has been updated / added (if needed)
• [x] tests have been updated / new tests has been added (if needed)

Please remove this line and everything above and fill the following sections:

JIRA link (if applicable)

https://tools.hmcts.net/jira/browse/CIV-14413

Change description

Dashboard notification for Applicant and Respondent when caseworker schedules the hearing

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

[ ] Yes
[ ] No

[karthick-mohanasundaram-HMCTS]

[karthick-mohanasundaram-HMCTS]