[Enhancement]: ScriptUtils::runInitScript should load script also from local directory

Module

Core

Proposal

The ScriptUtils::runInitScript only accepts paths from the classpath. This isn't as powerful as I would have expected given:

• Absolute paths or relative paths local to the maven module, for example, are useful as well
• Being on the classpath means the Maven compile (or test-compile) phase must have run, but what if I want to use testcontainers in the generate-sources (or generate-test-sources) phase, e.g. to generate jOOQ code? In that case, the init scripts aren't available on the classpath yet, unless I create a separate module just for this, which is overkill

Additionally, there are many cases where the script doesn't have to be a file. An inline script in String form would suffice, e.g.

container.initScript("""
  create schema test;
  create table test.test (test int);
""");

Inizia da ScriptUtils::runInitScript e dall’API container.initScript menzionata nella proposta. Segui il modo in cui vengono risolti gli script del classpath, quindi determina come devono essere accettati i percorsi locali assoluti o relativi e gli script String inline. Il lavoro è completato quando ogni forma di input supportata funziona e i test coprono i percorsi locali e l’SQL inline.