Added Mosquito Health Concerns symbols

[HeatherEisan]

Added Mosquito Health Concerns symbols to the following style files: ArcGISforLocalGovernmentWeb.style, ArcGISSolutionsWeb.style, and PublicWorksWeb.style.

• Chikungunya
• Dengue
• Encephalitis - (Eastern-Equine)
• Encephalitis - (Japanese)
• Encephalitis - (La-Crosse)
• Encephalitis - (Saint-Louis)
• Encephalitis - (Venezuelan-Equine)
• Encephalitis - (Western-Equine)
• Filariasis
• Malaria
• Mosquito Larvicide Sites
• Mosquito Surveillance Sites
• West Nile Virus
• Yellow Fever
• Zika Fever