Integers-as-names VLA naming convention

Antenna naming convention for VLA is such that the antenna names are actually valid integers converted to strings. While we feel that this is indeed a bad idea and it will be best to translate the VLA antenna names to something like VLA1, VLA2 in the CASA VLA filler (or something that does reflect that its a name and not get confused with integer indexes), for now, to accommodate the VLA tradition, the following logic is used:

Just for antenna selection, a user supplied integer (or integer list) is converted to a string and matched against the antenna name. If that fails, the normal logic of using an integer as an integer and matching it with antenna index is done.

Hence if the antenna with ID 17 is named "21", the string

"21",VLA22

will expand into an antenna ID list of 17,22 (assuming that the antenna named VLA22 has ID 22).

If we conclude that this style of antenna selection is indeed the way we wish to go, users should be aware that the antenna selection will behave differently for telescopes other than VLA. Assuming that antenna with names "21","17", and "11" have IDs 1,2,3 for VLA, a selection string "21,17,11" will select antenna with IDs 1,2,3. For other instruments where this is not the naming convention, the same selection string ("21,17,11") will select antennas with ID 21, 17, and 11.