Add modern TMS step CSV support

[satvik007]

Changes

• Emit one modern JSON Steps column instead of legacy numbered step columns.
• Add shared steps and typed text, link, and file step data.
• Add recursive validation, tests, documentation, and example usage.

Why

TMS imports now use the modern Steps JSON format. The library needs to generate that format while keeping the existing Step.Action and Step.Expected API.

Impact

Existing Go callers remain source-compatible. Generated CSV headers and step cells change to the modern format. Consumers that inspect legacy step columns must update.

Verification

• make test
• make build-examples
• make lint
• git diff --check

[sirkostya009]

didnt Andrian specifically kept old format as its more editable instead of the json

[satvik007]

didnt Andrian specifically kept old format as its more editable instead of the json

@sirkostya009 We have already made this decision in the product to have have steps json in the export csv. I don't see the point of someone using qasphere-csv library to create a csv only to manually edit it by hand.

Also let's be honest about the times we live in, no one edits anything by hand anymore.

[sirkostya009]

@satvik007 well he didn't like it last time we spoke on this so ask him