fix(client): add omitempty to additional optional DCR fields

Add omitempty JSON tag to client_name, owner, subject_type, and scope
fields to ensure they are omitted from JSON output when empty, per
RFC 7591 requirements for optional DCR fields.

Fixes #4044

Author: panbanda

client/.snapshots/TestHandler-common-case=create_clients-case=0-description=basic_dynamic_client_registration.json

@@ -1,13 +1,11 @@
 {
-  "client_name": "",
   "redirect_uris": [
     "http://localhost:3000/cb"
   ],
   "grant_types": null,
   "response_types": null,
   "scope": "offline_access offline openid",
   "audience": [],
-  "owner": "",
   "allowed_cors_origins": [],
   "client_secret_expires_at": 0,
   "subject_type": "public",

client/.snapshots/TestHandler-common-case=create_clients-case=1-description=basic_admin_registration.json

@@ -1,5 +1,4 @@
 {
-  "client_name": "",
   "client_secret": "averylongsecret",
   "redirect_uris": [
     "http://localhost:3000/cb"
@@ -8,7 +7,6 @@
   "response_types": null,
   "scope": "offline_access offline openid",
   "audience": [],
-  "owner": "",
   "allowed_cors_origins": [],
   "client_secret_expires_at": 0,
   "subject_type": "public",

client/.snapshots/TestHandler-common-case=create_clients-case=10-description=setting_skip_logout_consent_succeeds_for_admin_registration.json

@@ -1,5 +1,4 @@
 {
-  "client_name": "",
   "client_secret": "2SKZkBf2P5g4toAXXnCrr~_sDM",
   "redirect_uris": [
     "http://localhost:3000/cb"
@@ -8,7 +7,6 @@
   "response_types": null,
   "scope": "offline_access offline openid",
   "audience": [],
-  "owner": "",
   "allowed_cors_origins": [],
   "client_secret_expires_at": 0,
   "subject_type": "public",

client/.snapshots/TestHandler-common-case=create_clients-case=12-description=empty_ID_succeeds.json

@@ -1,5 +1,4 @@
 {
-  "client_name": "",
   "client_secret": "averylongsecret",
   "redirect_uris": [
     "http://localhost:3000/cb"
@@ -8,7 +7,6 @@
   "response_types": null,
   "scope": "offline_access offline openid",
   "audience": [],
-  "owner": "",
   "allowed_cors_origins": [],
   "client_secret_expires_at": 0,
   "subject_type": "public",

client/.snapshots/TestHandler-common-case=create_clients-case=4-description=non-uuid_works.json

@@ -1,6 +1,5 @@
 {
   "client_id": "not-a-uuid",
-  "client_name": "",
   "client_secret": "averylongsecret",
   "redirect_uris": [
     "http://localhost:3000/cb"
@@ -9,7 +8,6 @@
   "response_types": null,
   "scope": "offline_access offline openid",
   "audience": [],
-  "owner": "",
   "allowed_cors_origins": [],
   "client_secret_expires_at": 0,
   "subject_type": "public",

client/.snapshots/TestHandler-common-case=create_clients-case=5-description=setting_client_id_as_uuid_works.json

@@ -1,6 +1,5 @@
 {
   "client_id": "98941dac-f963-4468-8a23-9483b1e04e3c",
-  "client_name": "",
   "client_secret": "not too short",
   "redirect_uris": [
     "http://localhost:3000/cb"
@@ -9,7 +8,6 @@
   "response_types": null,
   "scope": "offline_access offline openid",
   "audience": [],
-  "owner": "",
   "allowed_cors_origins": [],
   "client_secret_expires_at": 0,
   "subject_type": "public",

client/.snapshots/TestHandler-common-case=create_clients-case=8-description=setting_skip_consent_succeeds_for_admin_registration.json

@@ -1,5 +1,4 @@
 {
-  "client_name": "",
   "client_secret": "2SKZkBf2P5g4toAXXnCrr~_sDM",
   "redirect_uris": [
     "http://localhost:3000/cb"
@@ -8,7 +7,6 @@
   "response_types": null,
   "scope": "offline_access offline openid",
   "audience": [],
-  "owner": "",
   "allowed_cors_origins": [],
   "client_secret_expires_at": 0,
   "subject_type": "public",

client/.snapshots/TestHandler-common-case=fetching_existing_client-endpoint=admin.json

@@ -1,14 +1,12 @@
 {
   "body": {
-    "client_name": "",
     "redirect_uris": [
       "http://localhost:3000/cb"
     ],
     "grant_types": [],
     "response_types": [],
     "scope": "offline_access offline openid",
     "audience": [],
-    "owner": "",
     "allowed_cors_origins": [],
     "client_secret_expires_at": 0,
     "subject_type": "public",

client/.snapshots/TestHandler-common-case=fetching_existing_client-endpoint=selfservice.json

@@ -1,14 +1,12 @@
 {
   "body": {
-    "client_name": "",
     "redirect_uris": [
       "http://localhost:3000/cb"
     ],
     "grant_types": [],
     "response_types": [],
     "scope": "offline_access offline openid",
     "audience": [],
-    "owner": "",
     "allowed_cors_origins": [],
     "client_secret_expires_at": 0,
     "subject_type": "public",

client/.snapshots/TestHandler-common-case=update_the_lifespans_of_an_OAuth2_client.json

@@ -8,7 +8,6 @@
     "response_types": [],
     "scope": "offline_access offline openid",
     "audience": [],
-    "owner": "",
     "allowed_cors_origins": [],
     "client_secret_expires_at": 0,
     "subject_type": "public",