Spring-ai Renable MongoDB tests

Added --add-opens=java.base/java.nio.charset=ALL-UNNAMED To the maven failsafe plugin configuration

Works around #698

Comment From: markpollack

This commit a1afb0db4644f216b3fead6142357fa468b7ca19 uses custom mongodb converters to fix the persistence issue. Let me know how it goes.

Comment From: rozza

Thats much better - thanks @markpollack 👍

Comment From: rozza

@markpollack having just reviewed I'm still hitting errors when running the tests:

[ERROR] Errors:
[ERROR]   MongoDBAtlasVectorStoreIT.documentUpdateTest:102->lambda$documentUpdateTest$2:108
 » InaccessibleObject Unable to make protected 
 java.nio.charset.Charset(java.lang.String,java.lang.String[]) accessible: module java.base 
 does not "opens java.nio.charset" to unnamed module @4fcb38dd

Note the tests are still disabled in MongoDBAtlasVectorStoreIT - so remove the annotation to see the error.