Update all dependencies incl typeorm 0.2.0 -> 0.3.0

[annarhughes]

What changes did you make?

Major update of all dependencies

Includes

• significant updates to all dependencies
• updated node version from v16 to v20
• major update from typeorm 0.2.0 -> 0.3.0 - see required changes below
• update to eslint config which fixed linting false positives. Many linting fixes applied once they were flagged e68a25d

Typeorm >0.3.0 changes - see guide for more details:

• removed ormconfig support and replaced with new DataSource
• all entities and migrations must now be imported to dataSourceOptions in typeorm.config.ts
• our custom repositories (e.g. /user/user.repository.ts) were causing errors (EntityMetadataNotFoundError) and as the custom repository didn't add any functionality, these were removed in favour of using the typeorm default Repository<UserEntity> - this caused the most file changes
• findOne replaced with findOneBy including many other function changes. We should complete a follow up review of all typeorm functions used in the app to ensure they are still the most efficient, vs new nesting join methods

Why did you make the changes?

• The updates were required for maintenance to improve performance and security. Triggered by issues running backend locally - which may have been a direct/indirect result of outdated packages.