Oracle connector

[huydo862003]

Summary

• [@dbml/connector] Support Oracle connector.
• [@dbml/connector] Move each connector to its respective folder.
• [@dbml/core] Fix a bug in Oracle importer where quoted data types are quoted 2 times. For example:

  CREATE TABLE "gold_users" (
  "birthday" "string COLLATE Latin1_General_CS_AS"
  );

would be translated to:

Table "gold_users" {
"birthday" ""string COLLATE Latin1_General_CS_AS"" // --> double quoted
}

Implementation details:

• The Oracle connector queries the "data dictionaries" of Oracle.
• We query the data dictionaries as the Oracle DBMS does not provide the INFORMATION_SCHEMA as detailed in the ANSI SQL standard:
  • StackOverflow: https://stackoverflow.com/questions/55037468/oracle-equivalent-of-information-schema-tables.
• Regarding the permission: https://docs.oracle.com/cd/A97385_01/server.920/a96524/c05dicti.htm.

     Any Oracle user can use the data dictionary as a read-only reference for information about the database.
  

Issue

(issue link here)

Lasting Changes (Technical)

(please list down: code changes/things that have wide-effect; new libraries/functions added that can be used by others; examples below)

• (Added class EmailValidator to validate email address' validity)
• (Added Tenant#is_trial? check)

Checklist

Please check directly on the box once each of these are done

• Documentation (if necessary)
• Lint checks
• Tests (integration test/unit test)
• Integration Tests Passed
• Code Review

[huyleminh01]

The pr looks good to me for now
Please help trigger the unit test action again to test the flaky case if exists nha. (can trigger 1 time) since we met the flaky test with ordinal position in connector before