QA/QE: Add to QA Dataset: Testing for converting Leads

[mkolodner]

Is your feature request related to a problem? Please describe.
Build in some testing for conversion of Leads, which apparently sometimes messes with DLRS.

Describe the solution you'd like
Create a Snowfakery recipe to generate Leads data a rollup summary that relates to it, and then automate some lead conversions and make sure rollups recalculate properly.

Recipe Content

Object: Lead
Count: 500
Fields:

• First Name
• Last Name
• Email
• Company (5 records should share the same company name)

[Nickers3]

At Feb 2024 Sprint, added a snowfakery dataset to include 20 leads. Did not make it so company names are the same for a subset though.
https://github.com/SFDO-Community/declarative-lookup-rollup-summaries/tree/feature/nw/rollup-lwc__feb-24-sprint-add-test-dlrs-rollups