Add priority bounds to challenge

[CollinBeczak]

Frontend implementation: maproulette/maproulette3#2681

This PR extends MapRoulette's challenge priority system by adding geographic bounds-based priority setting. Now, challenge creators can also set task priorities based on whether tasks fall within specific geographic boundaries.

Priority Resolution Logic

• Bounds take precedence: Geographic bounds are checked first, before property-based rules
• Fallback to rules: If no bounds match, the system falls back to existing property-based priority rules
• Default priority: If neither bounds nor rules match, uses the challenge's default priority

Database Changes

• Added three new nullable VARCHAR columns to the challenges table:
  • high_priority_bounds
  • medium_priority_bounds
  • low_priority_bounds

[sonarqubecloud]

Quality Gate failed

Failed conditions
13.9% Duplication on New Code (required ≤ 3%)

See analysis details on SonarQube Cloud