Wr/export junction objects

[WillieRuemmele]

What does this PR do?

allows multiple --query to data:export:tree

What issues does this PR fix or reference?

@W-5346871@

[shetzel]

QA

1. Linked the changes to my CLI
2. imported data to my scratch org (Account, Contact, AccountContactRelation)
3. exported data using multiple queries
4. inspected the data files that were generated ✅

Data export command:

sf data:export:tree --plan --output-dir junction --query "select AccountId, ContactId from AccountContactRole" --query "Select Id, AccountId, FirstName, LastName from Contact" --query "select Id, ContactId, AccountId from AccountContactRelation where Account.Name != 'We Know Everybody'" --query "select ID, Name from Account where Name != 'Sample Account for Entitlements'"