[!] add YAML-based chain definitions

[pashagolub]

Introduces support for defining task chains in YAML format, enhancing the readability and maintainability of chain configurations. Users can now define chains and tasks in a structured YAML file and load them directly into database.

Simplifies chain configuration compared to SQL inserts. Improves user experience with a human-readable format. Facilitates better version control and collaboration on chain definitions.

[coveralls]

Pull Request Test Coverage Report for Build 18127629475

Details

• 196 of 204 (96.08%) changed or added relevant lines in 7 files are covered.
• 62 unchanged lines in 4 files lost coverage.
• Overall coverage decreased (-1.9%) to 84.299%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/pgengine/bootstrap.go	24	25	96.0%
internal/pgengine/log_hook.go	1	2	50.0%
internal/scheduler/chain.go	2	4	50.0%
internal/pgengine/yaml.go	156	160	97.5%

Files with Coverage Reduction	New Missed Lines	%
internal/pgengine/transaction.go	1	99.23%
internal/scheduler/shell.go	9	74.29%
internal/pgengine/copy.go	12	42.62%
internal/scheduler/chain.go	40	68.86%

Totals
Change from base Build 18102127885:	-1.9%
Covered Lines:	1659
Relevant Lines:	1968

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💛 - Coveralls