Wire up HighNeedsService.Get() to underlying database views

[WolfyUK]

Context

AB#253438 AB#252392

Change proposed in this pull request

• Overrode stubbed version of the above service method
• Used correct database view dependent on dimension using new PlatformQuery, with test coverage
• Mapped result using Dapper multi mapping, with test coverage
• Fixed typo in VW_LocalAuthorityFinancialPerPopulation

Guidance to review

• Remaining stubbed service implementations with dependency on LA financials to be resolve as part of other work items.
• E2E and API tests will be in a failing state until seed data added as part of other work items. These are currently excluded from pipeline runs anyway, so this change should not block upstream deployments.
• Multi-mapping currently does not support CancellationToken. See QueryAsync with custom mapping AND CancellationToken DapperLib/Dapper#2125.

Checklist (add/remove as appropriate)

• Work items have been linked (use AB#)
• Your code builds clean without any errors or warnings
• You have run all unit/integration tests and they pass
• Your branch has been rebased onto main
• You have tested by running locally
• You have reviewed with UX/Design