Add WebGL, alerts and beacon statuses kanban

What's Changed

• Beacon statuses and alerts by @louptheron in #850
• Update beacons flow by @VincentAntoine in #944
• Rebased webgl vessel layer by @louptheron in #938
• UI review alerts & beacons by @louptheron in #947
• Take risk factors in last_positions table when raising alerts by @VincentAntoine in #956
• 345 afficher zone filtre by @thoomasbro in #917
• Fix memory leaks by @louptheron in #953
• Update RegulatoryLayerZoneMetadata panel by @AudreyBramy in #945
• Update position alerts filter on gears by @VincentAntoine in #963
• Add last searched vessels on click by @louptheron in #960
• Remove other properties from beacons or alerts to vessel identity object by @louptheron in #959
• Fix show alert from map by @louptheron in #968

Full Changelog: v1.5.1...v1.6.0