Create alternative way to use testcontainers in MUnit using fixtures

[alejandrohdezma]

🚀 What is included in this PR?

This PR includes an alternative way (more idiomatic) of using TestContainers with MUnit using fixtures.

Some examples:

class MysqlSpec extends FunSuite with TestContainersFixtures {

  val mysql = ForEachContainerFixture(MySQLContainer())

  // You need to override `munitFixtures` and pass in your container fixture
  override def munitFixtures = List(mysql)

  test("test case name") {
    // Inside your test body you can do with your container whatever you want to
    assert(mysql.container.jdbcUrl.nonEmpty)
  }
}

class MysqlSpec extends FunSuite with TestContainersFixtures {

  val mysql = ForAllContainerFixture(MySQLContainer())

  // You need to override `munitFixtures` and pass in your container fixture
  override def munitFixtures = List(mysql)

  test("test case name") {
    // Inside your test body you can do with your container whatever you want to
    assert(mysql.container.jdbcUrl.nonEmpty)
  }
}

class MysqlSpec extends FunSuite with TestContainersFixtures {
 
  val mysql = ContainerFunFixture(MySQLContainer())
 
  mysql.test("test case name") { container =>
    // Inside your test body you can do with your container whatever you want to
    assert(container.jdbcUrl.nonEmpty)
  }
}

[dimafeng]

@alejandrohdezma thank you so much! This looks great!

Would you mind adding a few examples to the readme?

[alejandrohdezma]

@dimafeng Done! 😸