[8.x] Solve the Primary Key issue in databases with sql_require_primary_key enabled

[khalilst]

This PR created in the following of this issue #33238 & here to solve the migration problem for databases with sql_require_primary_key enabled, (e.g. DigitalOcean machines).

It was OK for the auto-increment fields, but it was not working for other fields which need to be primary, e.g. the Passport Migration:

    $this->schema->create('oauth_auth_codes', function (Blueprint $table) {
        $table->string('id', 100)->primary();
        //Other fields
    });

In this situation, at first, the table was created and then altered to have a primary key on id.
So there were two queries executed to create the above table.

#The first one:
create table `oauth_auth_codes` (`id` varchar(100) not null) default character set utf8mb4 collate 'utf8mb4_unicode_ci';

#The second one:
alter table `oauth_auth_codes` add primary key `users_id_primary`(`id`);

This PR modifies the grammar to produce ONLY SINGLE QUERY like this:

create table `users` (`id` varchar(100) primary key not null) default character set utf8mb4 collate 'utf8mb4_unicode_ci'

This causes a tiny improvement during migrations especially for tests using RefreshDatabase middleware.
Also, the changes include MySQL, Postgres, SQL Server and SQLite with the required TESTS for all grammars.

[bjhijmans]

Does this also work for tables with compound primary keys? Such as:

Schema::create('hobby_user', function (Blueprint $table) {
    $table->uuid('hobby_id');
    $table->uuid('user_id');
    $table->primary(['hobby_id', 'user_id']);
}

I don't know if this can work, but it would make sense to me if the SQL generated in a Schema::create() or Schema::table() call always combined into a single query. That would also have the added bonus that an error in a column definition wouldn't leave a partially created or updated table.

[khalilst]

@bjhijmans No. It doesn't work for compound primary keys.
This PR only handles adding the primary key to a single field.
I may work on compound primary keys during another PR.
Also, I have to mention that the only way to create this kind of query is:

    $table->string('id', 100)->primary();

If you call the primary method using blueprint itself (not field), it generates the same ALTER query.

    $table->string('id', 100);
    $table->primary('id');

In support of altering the primary keys.