docs(examples): Add comprehensive test matrix and parallel execution …

…support - Fixes argoproj#8591

- Added test matrix to cover all E2E test cases.
- Introduced a DAG for parallel test execution to optimize runtime.
- Updated workflow steps for improved parallelism.
- Refactored code to use generic templates, reducing duplication and overall code length.
- Enhanced code readability by adding detailed comments.
- Added build step for the controller.

Signed-off-by: Wesley Scholl <[email protected]>