SG-32814 Review and unify code handling supported DCC versions

[julien-lang]

Differentiate warning messages between the oldest compatible version and the oldest supported version.

Changes aligned with other TK engines

• shotgunsoftware/tk-3dsmax#49
• shotgunsoftware/tk-alias#215
• shotgunsoftware/tk-houdini#81
• shotgunsoftware/tk-mari#30
• shotgunsoftware/tk-motionbuilder#36
• shotgunsoftware/tk-nuke#116
• shotgunsoftware/tk-vred#134

Screenshots

Note: Please ignore the exact versions in the screenshots below. I had to tweak the code to issue those.

• Error message when Maya version is older than the oldest compatible version

• Warning message when Maya version is older than the oldest supported version

• Warning message when Maya version is newer than the newest supported version