Require new plugins be submitted to a testing section first

[reiichi001]

Plogon should validate and enforce that any brand new plugin be submitted to one of the Testing sections first.

As we're still in the process of migrating from DalamudPlugins to DalamudPluginsD17, we may need to pull the current pluginmaster in order to check the plugin list, as we should skip over requiring a test release for plugins that were formerly on DalamudPlugins, but are new to D17. (But we should enforce it for any plugin that's new-new).