Make FBA table more usuable

As a FBAN/FBS I want to see a **_usable_** summary of fire behaviour indices and calculations So That I can quickly scan the context (e.g. severity) for stations crossing thresholds, and so that the required information per OSWS #5 is automatically generated

**Acceptance Criteria**
- [ ] Implemented consistently with Fire Behaviour Calculator (styling, labels)
- [ ] Table should be 50% of screen, Map is still 50% of screen (try flexbox instead of current grid layout)
- [ ] Remove nested scroll windows for table
- [ ] Make table header row sticky when scrolling vertically
- [ ] Make zone, station, & fuel type columns sticky when scrolling horizontally (confirm this w/ TG)
- [ ] Add loading indicator for table data

**Definition of Done**
- [ ] Ready to Demo in Sprint Review
- [ ] Does what I have made have appropriate test coverage?
- [ ] Documentation and/or scientific documentation exists and can be found
- [ ] Peer Reviewed by 2 people on the team
- [ ] Manual testing of all PRs in Dev and Prod
- [ ] Merged

Start by locating the current FBA table and map layout, then compare it with the Fire Behaviour Calculator for styling and labels. Work through the acceptance criteria for the split layout, scrolling, sticky headers and columns, and loading indicator; done means the table is usable alongside the map and ready for the stated demo and review process.

Written by the indexing model from the issue text.