Add "Get Salesforce mapped object" action

Problem/Motivation

When working with entities that are synchronized with Salesforce, users need a way to retrieve the mapping information to use with other Salesforce ECA actions.

Common use cases:

• Check if an entity has a Salesforce mapping
• Get the Salesforce ID for subsequent field retrieval
• Access sync status and timestamps
• View Salesforce URL for the mapped record

Steps to reproduce

1. Create an ECA model with "Content entity: View" event
2. Try to get Salesforce field values for the viewed entity
3. No way to get the Salesforce ID and object type needed

Proposed resolution

Add a focused action for retrieving mapped object information from entities.

Remaining tasks

• [x ] Create action plugin
• [x ] Use MappedObjectStorage::loadByEntity()
• [ x] Support optional mapping ID filter
• [x ] Return comprehensive mapping data as tokens
• [ ] Test with multiple mappings per entity

User interface changes

New action "Get Salesforce mapped object" will appear in ECA.

API changes

None.

Data model changes

None.