XSS injection fix

[Thorgathis]

I'm sorry to say that I'm not very fluent in English.

However, when using the chat function on the web map, you are able to run any script or insert any html tag you wish.

[jayzosayers]

Just to check have you tried running an actual script? Idk if it's meant to support formatting or not.

[exkc]

#638

i would say the original front end sanitized every html stuff for the chat but it seem it wont sanitized the description of marker so according to the original implementation this behaviour seem to be incorrect