chore(core-database-postgres): convert BYTEA to/from string (#3058)

* chore(core-database-postgres): convert BYTEA to/from string

Rename findMany and findManyWithCount to findAny and findAnyWithCount.
pg-promise has a method many() which throws if no rows are returned. It
also has a method any() which accepts 0, 1 or more rows as a result
(same as manyOrNone() or result()). Our findMany* methods do
not call the many() method but rather accept any number of rows as a
result.

packages/core-database-postgres/src/models/transaction.ts

@@ -53,7 +53,12 @@ export class Transaction extends Model {
         {
             name: "vendor_field",
             prop: "vendorField",
-            supportedOperators: [Database.SearchOperator.OP_LIKE],
+            init: col => col.value !== undefined ? Buffer.from(col.value, 'utf8') : undefined,
+            supportedOperators: [
+                Database.SearchOperator.OP_EQ,
+                Database.SearchOperator.OP_IN,
+                Database.SearchOperator.OP_LIKE
+            ],
             def: undefined,
         },
         {