[INLONG-5703][Manager] Add separator-related fields for some sources

[e-mhui]

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[INLONG-5703][Manager] Get separator from enum 'DataSeparator' and remove fieldDelimiter from properties of PulsarSource

• Fixes [Feature][Manager] Add separator-related fields for File, Kafka, and Pulsar sources #5703

Motivation

• DataSeparator is an ascii code, so we should get separator from enum DataSeparator
• if not remove fieldDelimiter, it will be parse into sql option. for example:

"properties": {
  "properties.auth-params": "token:xxxx",
  "properties.auth-plugin-classname": "org.apache.pulsar.client.impl.auth.AuthenticationToken",
  "fieldDelimiter": "|"
}