Fix REST path, process monitor, and Mongo EJSON test generation

[hoco-scy]

Summary

This PR fixes three independent failures observed while generating and running
EvoMaster tests across the WebFuzzing SUT suite:

• Fixes Generated Java tests fail to compile for Mongo EJSON values containing literal \u #1650: Java Mongo initialization source can contain a raw \\u
  sequence and fail compilation.
• Fixes REST test generation fails for lone-surrogate and non-ASCII path values #1651: REST path generation can fail for lone-surrogate and
  non-ASCII dynamic path values.
• Fixes Process monitor initializes shared output state even when disabled #1652: disabled process monitoring still initializes
  shared monitor output state, creating a concurrent filesystem race.

Changes

• Normalize Java-only Mongo EJSON backslash-u sequences with octal backslash
  escapes, preserving the EJSON runtime value while preventing Java Unicode
  preprocessing from rejecting generated source.
• Encode non-ASCII resolved REST path characters and retain URI rawPath for
  static path segments.
• Initialize process-monitor output only when process monitoring is enabled.

Evidence and Validation

• Reproduced the Mongo failure in generated genome-nexus source:
  EM_genome_nexus_True_True_0_1_Test.java, line 2534.
• Added MongoWriterTest for a literal \\uJTQGh EJSON value.
• Passed: mvn -pl core -Dtest=MongoWriterTest test.
• Passed a clean core build before the Mongo change:
  mvn -pl core -am clean package -DskipTests.
• Completed 36/36 one-configuration SUT validation with no controller-port,
  URI-surrogate, process_data, or DayOfMonth=0 errors.

Scope

The Mongo octal escaping applies only to Java output. Kotlin retains its
existing escaping path because Kotlin does not support Java octal string
escapes.

[arcuri82]

hi @hoco-scy !
you are a student of @man-zhang isn't it?
thanks for this PR ;)
as Man told you about docs/for_msc_bsc_students.md? once CI passes, ask @man-zhang for a review, and, when she will accept your updates/changes, she will ask for my review here on GitHub.
also, no need to create entries under issues (that is mainly for external users), you can just discuss them here directly in the PR description
thanks ;)