Renamed the boolean field "isNew" to "isNewBlock". This field when serialised to JSON and used in JavaScript (e.g. blockInfo.new as seen in Fieldbook's FieldMap.js: showBlockDetails() method) may cause a syntax/static code validation error and confuse some JS editors as "new" is a reserved keyword. Although a field named "new" in JSON does seem to work fine in some browsers, it is generally better to avoid using variable names which may end up clashing with reserved words.
Upgraded slf4j and logback libraries to latest available versions.

Issue: GCP-9132