Upgrade Java baseline to Java 17 and migrate starter to Spring Boot 3

[mfvanek]

• Update docs
• Remove spring-boot-integration/pg-index-health-test-starter/src/main/resources/META-INF/spring.factories
• consider to use records for modeling https://www.youtube.com/watch?v=7nYcOH5TRXU

[mfvanek]

We are going to single test like:

    @Autowired
    private List<DatabaseCheckOnHost<? extends DbObject>> checks;

    @Test
    void checksShouldWork() {
        assertThat(checks)
            .hasSameSizeAs(Diagnostic.values());
        checks.forEach(c -> assertThat(c.check()).isEmpty());
        checks.forEach(c ->
            switch (c.getDiagnostic()) {
                case BLOATED_TABLES:
                    assertThat(c.check())
                        .hasSize(1)
                        .containsExactlyInAnyOrder(
                            IndexWithBloat.of("t", "i", 0L, 0L, 0L)
                        );
                    break;
                case INVALID_INDEXES:
                    assertThat(c.check())
                        .hasSize(0);
                    break;
                default:
                    assertThat(c.check()).isEmpty();
            }
        );
    }

[mfvanek]

See assertj/assertj#772

    @SuppressWarnings("PMD.JUnitTestsShouldIncludeAssert")
    @Test
    void shouldWorkForPublicSchema() {
        checks.forEach(c -> {
            final List<? extends DbObject> checkResult = c.check();
            switch (c.getDiagnostic()) {
                case TABLES_WITHOUT_PRIMARY_KEY, TABLES_WITHOUT_DESCRIPTION -> assertThat(checkResult)
                    .asInstanceOf(list(Table.class))
                    .hasSize(1)
                    // HOW TO FIX: just add liquibase table to exclusions
                    .containsExactly(Table.of("databasechangelog", 0L));

                default -> assertThat(checkResult).isEmpty();
            }
        });
    }

[mfvanek]

Records cannot be used for models because of public constructors https://stackoverflow.com/questions/76843519/how-to-hide-constructor-on-a-java-record-that-offers-a-public-static-factory-met