Bug fix: Error when using custom versions (composer)

Fixes:

1. Fix version parsing when using custom version

Bug fix: Legacy operator compatibility to airflow 2

Fixes:

1. Compatibility and pod generation for airflow 2.

Bug fix: Deprecated functions

Fixes: Airflow 2 deprecated function and methods. (Mostly remove warnings and give proper references).

Feature: Allow support for noting the main container on Pod like elements

Support for feature: #46

Upgrade to support airflow 2.0.0

Changes:

1. Added support for changes in base class, to recognize and switch to airflow 2.0.0
2. Added support for path recognition in airflow 2.0.0
3. Added support for logging configuration in airflow 2.0.0

XCOM and kube log api events support

Added:

1. Airflow XCOM support.
2. ::kube_api:[event name]=[event value] in logs support

Container name and multi containers log

Fixes:

1. Pods with multi containers are error out. See issue #38

Added:

1. Container names to logs reader.

Removed extra logging

The configuration loading creates an unnecessary logging message.

Removed logging message.

Added KUBERNETES_JOB_OPERATOR_RESOURCES

Added env in executing pods which lists all the resources generated in the operation.
Env name: KUBERNETES_JOB_OPERATOR_RESOURCES

Jinja template arguments foreach operator instance

Added:

1. Allow each opeator to have its own, customized, jinja arguments.
2. Input argument jinja_job_args
3. appears in jinja as {{job.[my_arg]}}