Fire Behaviour Calculator (old) UI: move delete button - change hierarchy

**As a** *FBAN* **I want** *a clear and conventional interface* **So That** *table actions are clear and easy to use*

> Visual hierarchy is the arrangement of graphic elements in a design in order of importance of each element. The visual weight defines the importance of an element in a design's hierarchy, communicating to a viewer's eyes what to focus on and in what order.
If everything is important (the same weight, e.g. primary button), nothing is important. More cognitive effort required.

**Additional Context**
- "Add Row" remains primary button
- Export, reset, delete are styled as text links, grouped with table
-- proposing all 3 buttons are disabled until rows are selected (select 1, many, or all) action applies to selected rows
- [Figma file ](https://www.figma.com/file/AUhBnTB50dnY7ysoxBSqPN/New-Fire-Behaviour-Tool-2021?node-id=207%3A2)

**Acceptance Criteria**
- [ ] Given I am using FireBAT, When no rows are selected, Then the 3 table actions (export, reset, delete) are disabled
- [ ] Given I am using FireBAT, When 1+ row(s) are selected and I click delete, Then the selected rows are removed from the table

Start at the FireBAT table UI entry point and compare the current layout with the linked Figma file. Verify selection behavior and the export, reset, and delete actions; done means all three actions are disabled when no rows are selected and deleting removes every selected row.

Written by the indexing model from the issue text.