Add support for yugabytedb

[marccampbell]

Yugabyte Docs: https://docs.yugabyte.com/latest/api/ysql/commands/ddl_create_database

API

The proposal is to bump the schemahero API version from v1alpha4 to v1alpha5 during this, and create a webhook to convert them.

This will be a new DatabaseConnection field:

type DatabaseConnection struct {
	Postgres    *PostgresConnection    `json:"postgres,omitempty"`
	Mysql       *MysqlConnection       `json:"mysql,omitempty"`
	CockroachDB *CockroachDBConnection `json:"cockroachdb,omitempty"`
    YugabyteDB  *YugabyteDBConnection  `json:"yugabytedb,omitempty"`
}

type YugabyteDBConnection struct {
        UseYCQL *bool `json:"useYCQL,omitempty"`
	URI ValueOrValueFrom `json:"uri,omitempty"`

	Host     ValueOrValueFrom `json:"host,omitempty"`
	Port     ValueOrValueFrom `json:"port,omitempty"`
	User     ValueOrValueFrom `json:"user,omitempty"`
	Password ValueOrValueFrom `json:"password,omitempty"`
	DBName   ValueOrValueFrom `json:"dbname,omitempty"`
	SSLMode  ValueOrValueFrom `json:"sslmode,omitempty"`
}

Note that in the above spec, the user can choose to use YCQL or YSQL, with YSQL as the default. Both should be supported in the SchemaHero implementation.

Supported Features

All features should be supportable except for the following:

Alter table feature: yugabyte/yugabyte-db#1124

• COLLATE is unsupported: https://docs.yugabyte.com/latest/migrate/migrate-from-postgresql/migrate-schema/#remove-collation-on-columns
• Changing the Primary Key is unsupported ([YSQL] CREATE TABLE without a primary key followed by ALTER TABLE adding a primary key should end up with one primary key yugabyte/yugabyte-db#1104)

Testing and Verification

A new set of integration tests should be added to verify all supported operations on YugabyteDB.
We should run Yugabyte in a container in the CI process.
These should be release blocking failures.

Documentation

Docs are needed and will be worked on in parallel.