Fix issues found by latte linter

Most of the issues are translation keys using language keywords
("new", "default") without wrapping the key with quotes.

The remaining issues constisted of colon used to separate
arguments of latte filters (which is now deprecated).

remp/crm#2465

src/templates/PaymentsAdmin/new.latte

@@ -1,4 +1,4 @@
-{block #title}{_payments.admin.payments.new}{/block}
+{block #title}{_'payments.admin.payments.new'}{/block}
 
 {block head}
  <style>
@@ -13,10 +13,10 @@
 
 <div class="row">
  <div class="col-md-12">
- <a href="{link :Users:UsersAdmin:Show $user->id}"><i class="fa fa-angle-left"></i> {_payments.admin.payments.back_to_user}</a>
+ <a href="{link :Users:UsersAdmin:Show $user->id}"><i class="fa fa-angle-left"></i> {_'payments.admin.payments.back_to_user'}</a>
  <div class="page-header">
  <h1>
- {_payments.admin.payments.new_for_user} <small>{$user->public_name}</small>
+ {_'payments.admin.payments.new_for_user'} <small>{$user->public_name}</small>
  </h1>
  </div>
  </div>
@@ -46,7 +46,7 @@
  }).done(function(response) {
  $('#frm-paymentForm-variable_symbol').val(response.variable_symbol);
  }).fail(function() {
- alert({_payments.admin.payments.variable_symbol_error});
+ alert({_'payments.admin.payments.variable_symbol_error'});
  });
  return false;
  });
@@ -186,7 +186,7 @@
  return selected.indexOf(a) === -1;
  });
  var count = (function ask() {
- var n = prompt({_payments.admin.payments.enter_number_of_products}, 1);
+ var n = prompt({_'payments.admin.payments.enter_number_of_products'}, 1);
  return isNaN(n) ? ask() : n;
  }());