MINOR: specification: allow HAProxy variables in object name fields

Relax name regex on peer entries, nameservers, mailer entries, userlist
groups/users, and frontend log_tag to accept ${VAR} substitution. Section
names are unchanged.

Author: mjuraga

models/frontend_base.go

@@ -3578,7 +3578,7 @@ definitions:
         x-go-name: LogSteps
         x-omitempty: true
       log_tag:
-        pattern: ^[A-Za-z0-9-_.:]+$
+        pattern: ^[A-Za-z0-9-_.:${}]+$
         type: string
       logasap:
         enum:
@@ -4511,7 +4511,7 @@ definitions:
       secure_password:
         type: boolean
       username:
-        pattern: ^[A-Za-z0-9-_.:]+$
+        pattern: ^[A-Za-z0-9-_.:${}]+$
         type: string
         x-nullable: false
     required:
@@ -4533,7 +4533,7 @@ definitions:
         additionalProperties:
           type: object
       name:
-        pattern: ^[A-Za-z0-9-_.:]+$
+        pattern: ^[A-Za-z0-9-_.:${}]+$
         type: string
         x-nullable: false
       users:
@@ -4599,7 +4599,7 @@ definitions:
         additionalProperties:
           type: object
       name:
-        pattern: ^[A-Za-z0-9-_]+$
+        pattern: ^[A-Za-z0-9-_${}]+$
         type: string
         x-nullable: false
       port:
@@ -4688,7 +4688,7 @@ definitions:
         additionalProperties:
           type: object
       name:
-        pattern: ^[A-Za-z0-9-_.:]+$
+        pattern: ^[A-Za-z0-9-_.:${}]+$
         type: string
         x-nullable: false
       port:
@@ -11043,7 +11043,7 @@ definitions:
         additionalProperties:
           type: object
       name:
-        pattern: ^[A-Za-z0-9-_.:]+$
+        pattern: ^[A-Za-z0-9-_.:${}]+$
         type: string
         x-nullable: false
       port:

models/group.go

@@ -92,7 +92,7 @@ frontend_base:
       x-display-name: Log Format SD
     log_tag:
       type: string
-      pattern: '^[A-Za-z0-9-_.:]+$'
+      pattern: '^[A-Za-z0-9-_.:${}]+$'
     log_steps:
       type: array
       x-omitempty: true

models/mailer_entry.go

@@ -43,7 +43,7 @@ mailer_entry:
   properties:
     name:
       type: string
-      pattern: '^[A-Za-z0-9-_]+$'
+      pattern: '^[A-Za-z0-9-_${}]+$'
       x-nullable: false
     address:
       type: string

models/nameserver.go

@@ -63,7 +63,7 @@ peer_entry:
   properties:
     name:
       type: string
-      pattern: '^[A-Za-z0-9-_.:]+$'
+      pattern: '^[A-Za-z0-9-_.:${}]+$'
       x-nullable: false
     address:
       type: string