64-bit GenICam feature support

[MarkRivers]

GenICam integer features are 64-bit integers. However, the ADGenICam GenICam feature class declares these pure virtual methods:

   virtual int readInteger(void) = 0;
   virtual int readIntegerMin(void) = 0;
   virtual int readIntegerMax(void) = 0;
   virtual int readIncrement(void) = 0;
   virtual void writeInteger(int value) = 0;

This limits the range of such features to 32-bits, rather than the full 64-bit range that the camera may be using.

This has been shown to be an issue, for example, with the ChunkTimestamp feature on FLIR cameras, and likely on a number of other features on other cameras.

[MarkRivers]

This problem has been address by changing those methods in the GenICam feature class to this:

   virtual epicsInt64 readInteger(void) = 0;
   virtual epicsInt64 readIntegerMin(void) = 0;
   virtual epicsInt64 readIntegerMax(void) = 0;
   virtual epicsInt64 readIncrement(void) = 0;
   virtual void writeInteger(epicsInt64 value) = 0;

The derived classes in ADAravis, ADSpinnaker, and ADVimba have been changed to 64-bits. The ADGenICam driver has been changed to correctly handle 64-bit integer features.

makeDb.py has been changed to generate databases that can work with the new 64-bit integer features.

• Previously the GenICam integer feature records were longin/longout records, and hence limited to 32 bits.
• The new version generates either int64in/int64out records or ai/ao records.
• int64in/int64out is recommended on EPICS base versions 3.16.1 and later, including EPICS 7. Those versions provide the int64in and int64out records, which provide full access to the 64-bit GenICam features. These records are used if the --devInt64 option is passed to makeDb.py.
• For older versions of EPICS base the --devInt64 option cannot be used, because the int64in/out records are not supported. In this case makeDb.py now uses ai/ao records. The VAL field in these records is a 64-bit float, which can exactly represent integers up to 52 bits long. This is sufficient for many of the large integers in GenICam.

This new support is available for testing in the master branch of ADGenICam, ADAravis, ADSpinnaker, and ADVimba.

int64in/out records require asyn R4-47. asynInt64 device support for ao/ai records requires the master branch of asyn.