Add better parchment version validation

[LexManos]

Addresses #12 and MinecraftForge/ForgeGradle#988

Example error:

Exception in thread "main" java.lang.IllegalArgumentException: Parchment snapshots are not supported: 2025.04.19-SNAPSHOT
	at net.minecraftforge.mcmaven.impl.mappings.ParchmentVersion.parse(ParchmentVersion.java:72)
	at net.minecraftforge.mcmaven.impl.mappings.ParchmentMappings.<init>(ParchmentMappings.java:41)
	at net.minecraftforge.mcmaven.cli.MCPDataTask.runI(MCPDataTask.java:119)
	at net.minecraftforge.mcmaven.cli.MCPDataTask.run(MCPDataTask.java:33)
	at net.minecraftforge.mcmaven.cli.Main.run(Main.java:57)
	at net.minecraftforge.mcmaven.cli.Main.main(Main.java:21)

I also designed the ParchmentVersion class to be fairly standalone so that it can be used in FG to sanitize user input.
Pushing this before i got to bed, if Paint or Jonathing give it a quick sanity test and we can pull it tomarrow.