[IMP] mail, *: move up model files

Move model definition files from `models/thing/thing.js` to
`models/thing.js` and remove the now empty intermediate directory.

Task-2759582
 * = calendar, crm_livechat, hr, im_livechat, mail_bot, sms, snailmail,
     website_livechat, website_slides

closes odoo/odoo#86464

Related: odoo/enterprise#25291
Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>

addons/hr/static/src/models/messaging.js

@@ -2,7 +2,7 @@
 
 import { patchRecordMethods } from '@mail/model/model_core';
 // ensure that the model definition is loaded before the patch
-import '@mail/models/messaging/messaging';
+import '@mail/models/messaging';
 
 patchRecordMethods('Messaging', {
     /**

addons/hr/static/src/models/partner.js

@@ -3,7 +3,7 @@
 import { addFields, addRecordMethods, patchRecordMethods } from '@mail/model/model_core';
 import { attr, one } from '@mail/model/model_field';
 // ensure that the model definition is loaded before the patch
-import '@mail/models/partner/partner';
+import '@mail/models/partner';
 
 addRecordMethods('Partner', {
     /**

addons/hr/static/src/models/user.js

@@ -3,7 +3,7 @@
 import { addFields } from '@mail/model/model_core';
 import { one } from '@mail/model/model_field';
 // ensure that the model definition is loaded before the patch
-import '@mail/models/user/user';
+import '@mail/models/user';
 
 addFields('User', {
     /**