Configurable DB Params: Add test coverage for nullable fields

[ykim-akamai]

📝 Description

Add test coverage for nullable field:

• MySQL: innodb_ft_server_stopword_table
• PostgreSQL: None

Password Encryption in PG DB will default to "md5" when nothing or null value is specified

✔️ How to Test

╰─➤  make test-int TEST_CASE=test_create_postgres_db_password_encryption_default_md5 RUN_DB_TESTS=yes
╰─➤  make test-int TEST_CASE=test_create_mysql_db_nullable_field RUN_DB_TESTS=yes 

📷 Preview

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[ezilber-akamai]

Thanks for addressing this! Tests are passing locally.