Delta Lake input source: add support for user-provided configuration

[yurmix]

Description

The Delta Kernel API accepts Hadoop config via the Engine interface. However, DeltaInputSource hides this and instantiates the engine with an empty Configuration().

It is proposed to add a hadoopProperties JSON field to the Delta Lake input source.
Example:

"inputSource": {
  "type": "delta",
  "tablePath": "s3a://bucket/path/to/table",
  "hadoopProperties": {
    "fs.s3a.access.key": "${AWS_ACCESS_KEY_ID}",
    "fs.s3a.secret.key": "${AWS_SECRET_ACCESS_KEY}",
    "fs.s3a.session.token": "${AWS_SESSION_TOKEN}",
    "fs.s3a.endpoint": "s3.amazonaws.com"
  }
}

Motivation

Allow providing Hadoop properties such as S3A credentials, endpoints, and similar options at the ingestion spec level rather than globally.

This enables ingesting from different environments and adding configuration specific to the ingestion task.

Example use case: support reading Delta tables from S3 with temporary AWS STS credentials without relying on global configuration.

[yurmix]

Also, I am wondering if this should support Dynamic Config Providers, in case the goal is to provide credentials.
This would be similar to how catalogProperties was implemented by @a2l007 for Iceberg input source.