Mission - Add Mark Buildings Function

[Mike-MF]

When merged this pull request will:

• Adds a function to mark buildings the same way the map objects are done. (See image on VR)
• It's not exactly fast depending on how many objects are in the array, but wouldn't be noticeable on mission start.

Marker name has to be unique, only thing I could think of that makes it so is using the object position. Examples:

"2293.223775.22-4.76837e-007"
"2329.533795.150"
"2373.953806.670"
"2330.523794.51-0.00336075"
"2356.343912.850"
"2343.283912.930"
"2330.373912.780"
"2317.313912.870"
"2304.33912.80"

[Mike-MF]

Works