Fix merge button (#15899)

Fixes https://github.com/twentyhq/private-issues/issues/362

**How to reproduce**
Link a person that has a duplicate to an opportunity. (you can create a
duplicate by giving two people the same linkedin link).
Open the opportunity record from opportunity table. 
Click on the related person (in "Point of contact").
In front of "Duplicates", click on the merge button (two arrows becoming
one).
You should here see an empty "Merge preview" and an error when clicking
"First" tab.

**Issue**
The issue is that CommandMenuMergeRecordPage is getting the referenced
objectMetadataItem from useContextStoreObjectMetadataItemOrThrow without
an instance id. contextStoreObjectMetadataItem is still "opportunity" as
it should be, being on an opportunity view.
So further down it attempts to display the record page according the
label identifier field from opportunity, which is a text field, "name",
and it breaks because the record is actually a person for who the "name"
field is not a text but a full_name type.

**Fix**
I suggested a fix that offers the possibility to find the referenced
objectMetadataItem from the MergeRecords instanceId. But I still gave
flexibility to avoid having to set that state everytime we open the
merge tab, by falling back to the default
contextStoreObjectMetadataItem. (this is used when we merge records from
ticking two records from a view and open the command menu).
Im not sure this is the best option. Open to suggestions !

---------

Co-authored-by: Charles Bochet <charles@twenty.com>

packages/twenty-server/src/engine/api/common/common-query-runners/common-merge-many-query-runner.service.ts

@@ -5,10 +5,10 @@ import {
   QUERY_MAX_RECORDS,
 } from 'twenty-shared/constants';
 import {
+  FieldMetadataRelationSettings,
   FieldMetadataType,
   ObjectRecord,
   RelationType,
-  FieldMetadataRelationSettings,
 } from 'twenty-shared/types';
 import { isDefined } from 'twenty-shared/utils';
 import { FindOptionsRelations, In, ObjectLiteral } from 'typeorm';
@@ -95,7 +95,7 @@ export class CommonMergeManyQueryRunnerService extends CommonBaseQueryRunnerServ
     });
 
     await queryBuilder
-      .softDelete()
+      .delete()
       .whereInIds(idsToDelete)
       .returning(columnsToReturn)
       .execute();