Add "Entity Has Salesforce Mapping" condition

Problem/Motivation

Workflows often need to check if an entity type/bundle has any Salesforce mapping configured before attempting sync operations.

This condition would enable:
- Conditional workflow execution based on mapping existence
- Preventing errors when no mapping exists
- Building dynamic workflows that adapt to configuration

Steps to reproduce

1. Create an ECA model
2. Need to check if entity has Salesforce mapping
3. No simple condition available

Proposed resolution

Add a condition plugin that checks if the entity type/bundle has any active Salesforce mapping.

Remaining tasks

- [ ] Create condition plugin
- [ ] Query mapping storage for entity type/bundle
- [ ] Return TRUE/FALSE
- [ ] Test with various entity types

User interface changes

New condition "Entity has Salesforce mapping" will appear in ECA.

API changes

None.

Data model changes

None.