refactor(core): eslint errors warns

[jorgenavben]

Description

This pull request focuses on fixing existing ESLint issues in the codebase to enhance code quality and ensure adherence to coding standards. Additionally, it introduces plans to integrate ESLint checks into the pipeline, potentially as a post-OSS activity.

Checklist before requesting a review

Issue ticket number and link

• This PR has a valid ticket number or issue: DTIS-460

Testing & Validation

• This PR has been tested/validated in IOS, Android and browser.
• The code has been tested locally with test coverage match expectations.
• Added new Unit/Component testing (if relevant).

Security

• No secrets are being committed (i.e. credentials, PII)
• This PR does not have any significant security implications

Code Review

• There is no unused functionality or blocks of commented out code (otherwise, please explain below)
• In addition to this PR, all relevant documentation (e.g. Confluence) and architecture diagrams (e.g. Miro) were updated