feat: improved permission handling for MapFormField

This PR enables a center to be defined while still requesting and gracefully handling a current location call (which prompts permission check). This is to allow user testing with the following workflow.

This might be temporary since in reality we probably don't need to ask for the user's location if we don't intend to actually use it.

Technical changes include:

• useEffect with useRef to only run once
• use const variables instead of modifying readonly props
• only store get location result if center is not defined in props
• add alerts for warning conditions such as not being able to access location
• add alerts for using default map center location (no current location available AND no configured center location) - this defaults to Sydney

How to Test

Try different permutations of permissions yes, no, ask, as well as providing and not providing a center in the notebook definition. Check it always respects the center provided, shows errors where appropriate, and notifications work.

Checklist

• I have confirmed all commits have been signed.
• I have added JSDoc style comments to any new functions or classes.
• Relevant documentation such as READMEs, guides, and class comments are updated.