[Feature] List files from inputDir with recursive option based on inputFilePatterns in IngestionJobLauncher

[61yao]

[61yao]

As discussed, the new implementation also adds the behavior that when input file pattern is null, we also do recursive search in root dir since there are unit test that covers this so I think it should be current default behavior. We may need more discussion on how we want to handle this.

[61yao]

After thinking about it again, I feel getting the recursive option from the input file pattern is safer and cleaner.

It doesn't break existing usage and it performs better. The code is also cleaner.

Adding an searchRecursively option and setting it to false by default is dangerous because it is different from existing behavior.