[pavog]

[16:24:35 ERROR]: Fatal error trying to convert LegacyBrokenClass v1.0:com/repro/BrokenClass.class
java.lang.ArrayIndexOutOfBoundsException: Index 1 out of bounds for length 1
	at org.bukkit.craftbukkit.util.Commodore.convert(Commodore.java:210) ~[paper-26.3.jar:26.3-248-0727243]

When CraftBukkit could not convert a class of a legacy plugin (no api-version in its plugin.yml), nothing was detected.
This PR adds a problem for it that names the plugin and suggests installing a different version or removing it.

The problem lives in Bukkit, because the message comes from CraftMagicNumbers in CraftBukkit, so Paper and Folia inherit it.
The log contains the full name of the plugin (Name v1.0), so the pattern only captures the name before v.
It extends PluginProblem to reuse PluginInstallDifferentVersionSolution and PluginRemoveSolution, and it is reported once per plugin even if several classes fail.

The warning Legacy plugin ... does not specify an api-version. is not covered here.

Changes

• add LegacyPluginConversionProblem and register it in BukkitAnalyser
• add the legacy-plugin-conversion-problem translation
• add the paper-legacy-plugin-conversion-26-3.log fixture