Activity as standard object (#6219)

In this PR I layout the first steps to migrate Activity to a traditional
Standard objects

Since this is a big transition, I'd rather split it into several
deployments / PRs

<img width="1512" alt="image"
src="https://github.com/user-attachments/assets/012e2bbf-9d1b-4723-aaf6-269ef588b050">

---------

Co-authored-by: Charles Bochet <charles@twenty.com>
Co-authored-by: bosiraphael <71827178+bosiraphael@users.noreply.github.com>
Co-authored-by: Weiko <corentin@twenty.com>
Co-authored-by: Faisal-imtiyaz123 <142205282+Faisal-imtiyaz123@users.noreply.github.com>
Co-authored-by: Prateek Jain <prateekj1171998@gmail.com>

packages/twenty-server/src/engine/api/rest/core/query-builder/utils/map-field-metadata-to-graphql-query.utils.ts

@@ -30,6 +30,7 @@ export const mapFieldMetadataToGraphqlQuery = (
     FieldMetadataType.MULTI_SELECT,
     FieldMetadataType.POSITION,
     FieldMetadataType.RAW_JSON,
+    FieldMetadataType.RICH_TEXT,
   ].includes(fieldType);
 
   if (fieldIsSimpleValue) {