refactor: standardize JsonStringified casing (#20101)

## Summary
- Rename safeParseRelativeDateFilterJSONStringified to
safeParseRelativeDateFilterJsonStringified
- Update the matching utility file, exports, tests, and workflow usages

Part of #19839.

## Validation
- CI passed

packages/twenty-shared/src/utils/index.ts

@@ -159,7 +159,7 @@ export { parseJson } from './parseJson';
 export { removePropertiesFromRecord } from './removePropertiesFromRecord';
 export { removeUndefinedFields } from './removeUndefinedFields';
 export { resolveRichTextVariables } from './rich-text-variable-resolver';
-export { safeParseRelativeDateFilterJSONStringified } from './safeParseRelativeDateFilterJSONStringified';
+export { safeParseRelativeDateFilterJsonStringified } from './safeParseRelativeDateFilterJsonStringified';
 export { getGenericOperationName } from './sentry/getGenericOperationName';
 export { getHumanReadableNameFromCode } from './sentry/getHumanReadableNameFromCode';
 export { appendCopySuffix } from './strings/appendCopySuffix';