feat: Allow unicode javadoc comments

[lqiu96]

Fixes #161

This is the new ...Field.Builder.yml file:

- uid: "com.google.cloud.bigquery.Field.Builder.setPrecision(java.lang.Long)"
  id: "setPrecision(java.lang.Long)"
  parent: "com.google.cloud.bigquery.Field.Builder"
  langs:
  - "java"
  name: "setPrecision(Long precision)"
  nameWithType: "Field.Builder.setPrecision(Long precision)"
  fullName: "com.google.cloud.bigquery.Field.Builder.setPrecision(Long precision)"
  overload: "com.google.cloud.bigquery.Field.Builder.setPrecision*"
  type: "Method"
  package: "com.google.cloud.bigquery"
  summary: "Precision can be used to constrain the maximum number of total digits allowed for NUMERIC or\n BIGNUMERIC types. It is invalid to set values for Precision for types other than // NUMERIC\n or BIGNUMERIC. For NUMERIC type, acceptable values for Precision must be: 1 ≤ (Precision -\n Scale) ≤ 29. Values for Scale must be: 0 ≤ Scale ≤ 9. For BIGNUMERIC type, acceptable values\n for Precision must be: 1 ≤ (Precision - Scale) ≤ 38. Values for Scale must be: 0 ≤ Scale ≤\n 38."
  syntax:
    content: "public Field.Builder setPrecision(Long precision)"
    parameters:
    - id: "precision"
      type: "java.lang.Long"
    return:
      type: "com.google.cloud.bigquery.Field.Builder"

Issue seems to be from bodyItem.toString() (https://www.javadoc.io/static/org.kohsuke.sorcerer/sorcerer-javac/0.11/com/sun/tools/javac/tree/DCTree.DCText.html) which renders the with unicode escapes. Use apache-commons-text to render the unicode escapes back to unicode values.

[suztomo]

I wondered Guava can do the same job but it seems not https://stackoverflow.com/questions/34091304/does-guava-provide-a-method-to-unescape-a-string

[suztomo]

This version is safe. But commons text is often marked as CVEs.

https://security.netapp.com/advisory/ntap-20221020-0004/