Macro recursion decrease and other optimizations

- Decreased `recursion_limit` from 512 to 87
  Mainly done by optimizing the config macro's.
  This fixes an issue with the rust-analyzer which doesn't go beyond 128
- Removed Regex for masking sensitive values and replaced it with a map()
  This is much faster then using a Regex.
- Refactored the get_support_json macro's
- All items above also lowered the binary size and possibly compile-time
- Removed `_conn: DbConn` from several functions, these caused unnecessary database connections for functions who didn't used that at all
- Decreased json response for `/plans`
- Updated libraries and where needed some code changes
  This also fixes some rare issues with SMTP https://github.com/lettre/lettre/issues/678
- Using Rust 2021 instead of 2018
- Updated rust nightly

src/api/core/accounts.rs

@@ -454,7 +454,7 @@ fn post_email(data: JsonUpcase<ChangeEmailData>, headers: Headers, conn: DbConn)
 }
 
 #[post("/accounts/verify-email")]
-fn post_verify_email(headers: Headers, _conn: DbConn) -> EmptyResult {
+fn post_verify_email(headers: Headers) -> EmptyResult {
     let user = headers.user;
 
     if !CONFIG.mail_enabled() {
@@ -654,7 +654,7 @@ struct VerifyPasswordData {
 }
 
 #[post("/accounts/verify-password", data = "<data>")]
-fn verify_password(data: JsonUpcase<VerifyPasswordData>, headers: Headers, _conn: DbConn) -> EmptyResult {
+fn verify_password(data: JsonUpcase<VerifyPasswordData>, headers: Headers) -> EmptyResult {
     let data: VerifyPasswordData = data.into_inner().data;
     let user = headers.user;