ASA: Add topographic position information to advisory bulletin

[nealmcloughlin]

Describe the task
Update the automated text bulletin for fire zone advisories and warnings to be more descriptive about what topographic positions are of concern based on percentage of each topographic position under advisory.

Acceptance Criteria

• Auto-generated text includes topographic positions to watch out for whenever the percentage of a topographic position (valley bottom, mid slope, upper slope) under advisory is >50%. If the percentage of a topographic position is <= 50% then it is not mentioned in the text bulletin.

Additional context

• Refer to updated percentages in ASA: TPI percentages in dashboard infographic #4194
• Here is example wording: "There is a fire behaviour Advisory in effect for G3-Robson Valley Fire Zone between 08:00 and 23:00. C-3 and C-7 fuel types account for 75% or more of today's total advisory area. Also watch out for C-2 and S-3 fuel types which occupy a small portion of the zone but are expected to be under advisory conditions wherever they occur. Advisory conditions are expected across 65% of valley bottoms."

Definition of Done
https://github.com/bcgov/wps/wiki/Definition-of-Done