Proposal for further annotation cleanup

[NotMyFault]

In https://github.com/IntellectualSites/PlotSquared/commit/3eb485e90043ee64df78fbecaa83686e3b27b598 I dropped informational Guava and JB annotations and reduced our overall annotation library count from 6 to 5. This is a proposal to determine which frameworks are needed still or can be removed or transitioned to checkerqual, our core annotation framework. All annotation frameworks mentioned are shaded and provided at runtime.

• JB (org.jetbrains) Used only in Fawe classes and a single time in ClickStripTransform, looks like a wrong import. To match with upstream, Fawe switched to javax some months ago. We can adapt the changes and remove JB overall.

• IJ Lang (org.intellij.lang) I couldn't find a single use case in the code, it provides @Language, @Pattern and @RegExp at runtime, do we need it for some third party dependency?

• JavaX (javax.annotation) Used in a few injectable classes. Originally introduced when we switched to Guice 4, because Guice didn't recognize nullability provided by qual. We are now using Guice 5 and should evaluate again whether that is still true. It is used in PlotTitle as well, which is non injectable. Edit: Taking a look at the Guice documentation, checkerqual nullability is supported.

• JSR 305 (com.google.code.findbugs) Required for cloud until the JavaX scenario from above has been evaluated.

• JSR 330 (javax.inject) We don't use that a single time in our codebase, our @Inject and @Singleton is provided by Guice. To my knowledge, JSR 330 has been published in 2009, do we really have dependencies that demand such ancient libraries?