feat(share, config): more variables, placeholder and reset default (#132)

* More email share vars + unfinished placeolders config

{desc} {expires} vars
(unfinished) config placeholder vals

* done

* migrate

* edit seed

* removed comments

* refactor: replace dependecy `luxon` with `moment`

* update shareRecipientsMessage message

* chore: remove `luxon`

* fix: grammatically incorrect `shareRecipientsMessage` message

* changed to defaultValue and value instead

* fix: don't expose defaultValue to non admin user

* fix: update default value if default value changes

* refactor: set config value to null instead of a empty string

* refactor: merge two migrations into one

* fix value check empty

---------

Co-authored-by: Elias Schneider <login@eliasschneider.com>

backend/prisma/schema.prisma

@@ -131,15 +131,16 @@ model ShareSecurity {
 model Config {
   updatedAt DateTime @updatedAt
 
-  name        String
-  category    String
-  type        String
-  value       String
-  description String
-  obscured    Boolean @default(false)
-  secret      Boolean @default(true)
-  locked      Boolean @default(false)
-  order       Int
+  name         String
+  category     String
+  type         String
+  defaultValue String @default("")
+  value        String?
+  description  String
+  obscured     Boolean @default(false)
+  secret       Boolean @default(true)
+  locked       Boolean @default(false)
+  order        Int
 
   @@id([name, category])
 }