[bugfix] Replace CronUtils library

[maxim-mityutko]

Description

As stated in the #195, using CronUtils library on DBR 15.4 is impossible due to lack of access to JVM. This library is available for Java only. Hence I've implemented custom code to convert between unix cron and quartz cron and removed the dependency on the said library.

Currently not all features of the Quartz expression are supported, namely: L W and # keys.

Related Issue

#195

Motivation and Context

Brickflow can't be used with DBR 15.4 and future versions as long as plugins are required.

How Has This Been Tested?

• unit tests
• TODO: deploy existing workflow and test in DBX

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.