Restore Pos conversion to mcDEFAULT homing mode

[AndrewMusser]

This PR modifies AxisLib's reference FUB to handle restore pos homing modes differently. The general idea is to leverage more of Mapp Motion's 'out-of-the-box' capabilities with Restore Pos homing:

• It still requires that the RestorePosition PV be passed in, but it commands a home default for axes that have a non-zero restore pos PV.
• This means that the RestorePosition PV must also be linked in the drive's configuration for this to work.
• The reason it is still passed in to AxisLib is so that we can check whether or not the data is valid.

[Joshpolansky]

@AndrewMusser Do you remember anything about this?

[AndrewMusser]

@AndrewMusser Do you remember anything about this?

@Joshpolansky Yes, vaguely. I think we did this because Mapp Motion handles the restore pos in an automated way for you when you map a PV in the drive's configuration?

[Joshpolansky]

@AndrewMusser Do you remember anything about this?

@Joshpolansky Yes, vaguely. I think we did this because Mapp Motion handles the restore pos in an automated way for you when you map a PV in the drive's configuration?

Was there a reason we didn't use it?

[Joshpolansky]

Based on testing with MpRobotFlex I'm not sure the drive automatically handles the homing if data is valid. Is that your understanding? I was wondering if it's MpAxisBasic that does the restore pos?