[BUG]: SQLite adapter does not support NOT NULL columns with default values

[zsilbi]

Describe the bug

When creating a new Model the Adapter will throw an Exception like the following, if:

• the schema has columns with default values
• these fields are not defined/null in the inserted model

[PDOException] SQLSTATE[23000]: Integrity constraint violation: 19 NOT NULL constraint failed: 
co_customers_defaults.cst_status_flag

The SQLite adapter will create the following statement:

INSERT INTO "co_customers_defaults" ("cst_status_flag", "cst_name_last", "cst_name_first", "cst_id") 
VALUES (NULL, NULL, NULL, null)

NULL is inserted for the 3 unset fields, because Db\Adapter\Pdo\Sqlite::getDefaultValue() returns new RawValue('NULL') for any unset fields that have default values in MetaData (This works well for MySQL with RawValue('DEFAULT'))

To Reproduce

create table co_customers_defaults
(
    cst_id          integer constraint co_customers_defaults_pk primary key autoincrement,
    cst_status_flag integer      not null DEFAULT 1,
    cst_name_last   text         not null DEFAULT 'cst_default_lastName',
    cst_name_first  text         not null DEFAULT 'cst_default_firstName'
);

class CustomersDefaults extends Model
{
    public $cst_id;
    public $cst_status_flag;
    public $cst_name_last;
    public $cst_name_first;

    public function initialize()
    {
        $this->setSource('co_customers_defaults');
    }
}

$customer = new CustomersDefaults();
$customer->create(); // Should return true

Tested here: https://github.com/phalcon/cphalcon/pull/15179/checks?check_run_id=1271542325

Proposed solution:

Modify Db\Adapter::getDefaultValue() to return false when it's not supported by the adapter. (Breaks BC, maybe a new method could be added until 6.0)
Modify Mvc\Model not to include these fields in the statements when the adapter doesn't support it:

INSERT INTO "co_customers_defaults" ("cst_id") VALUES (null)

cc @phalcon/core-team

[zsilbi]

Resolved in #15182