feat: add suppressDuplicateTaskError through configuration

[smmcbride]

node-resque defines the suppressDuplicateTaskError flag when scheduling a task at a time that it is already scheduled. This PR adds that flag to the configuration and passes it through when calling node-resqueue's enqueueIn or enqueueAt functions.

[shiny]

Appreciate the pull request! I’ll check it out later.

[shiny]

Currently, when a task is already scheduled, it returns undefined, which is inconsistent with the Promise<boolean | boolean[]> return type. Do you think it would be better to add undefined or null to the return type definition, or treat the suppressed duplicate case as a boolean false result instead?