Limit the size of search area and adjust search tile size

jirikadlec2[CodePlex]
In areas with very high density of sites, the search takes very long time and returns too many results (slow to display on the map). Also the tile size (1x 1 degree is too large which prevents frequent reporting of progress. As a temporary measure in 1.3,
impose a limit on maximum allowed selected area and reduce the search tile size in areas of very high site density.

Maximum search area: This is the intersection of the selected area (rectangle or polygons) and the selected web service bounding boxes.

The maximum search area should be 500,000 square kilometers in low-density regions.

The maximum search area should be 100,000 square kilometers in high-density regions.

Definition of high density regions is: North-East USA, Texas. The simplified polygon coordinates of these regions are attached.

Definition of low density regions is: all other regions.

Search tile size for high density regions: 0.25 x 0.25 degrees
Search tile size for low density regions: 1 x 1 degrees

The selected search area is assumed to be a high density region if it is completely within a high density region.

Note: The values of maximum search area, and search tile size will change in the future as the search server mechanism improves. If a 'paged' query is added to the catalog in the future, the tile approach may no longer be needed. For 1.3, make the area and
tile size parameters and high density polygons configurable (read from search3.dll.config) so that they can be easily adjusted if required

Locate the search-area and tile-processing entry points, then inspect search3.dll.config and the selected-area/service-bounding-box flow. Done means the configured limits, high-density polygons, and density-specific tile sizes control searches while preserving progress reporting; verify behavior for both high- and low-density regions.

Written by the indexing model from the issue text.