This extension is useful to find out how much disk space is occupied by
temporary tables and which user created them in which session.
The extension tracks the creation and deletion of temporary table files on
segments. The list of files is stored in the shared memory of each segment.
If memory allocated using ShmemInitStruct is not enough, the extension uses DSM.
The extension adds the tts_get_seg_files function to get the tracked files,
their sizes, user and session where they was created from segments.
Add the ic-temp_tables_stat test for the extension.