Introduce new lambda step API

[baev]

fixes #232

Add test links

link("testing", "https://example.com");
issue("GH-123", "https://github.com/allure-framework/allure2/issues/123");
tms("AS-182", "https://allureee.qameta.io/project/1/test-cases/182");

Add test labels

epic("Allure Java API");
feature("Dynamic API");
label("component", "allure-java-commons");

Add parameters to test within test body

String baseUrl = parameter("baseUrl", "https://example.com/getData");

Log-style steps

step("set up test database", Status.SKIPPED);
step("set up test create mocks"); // Status.PASSED by default

Add parameters to test inside steps as well

String token = step("authorization", () -> {
    String login = parameter("login", "admin");
    String password = parameter("password", "admin");
    return getAuth(login, password);
});

Add parameters to step using injected StepContext

step("preparation checks", (step) -> {
    step.parameter("a", "a value");
    step.parameter("b", "b value");
});

Nested step and dynamic step name

step((step) -> {
    String a = step("child 1", () -> "A");
    String b = step("child b", () -> "B");
    String c = step("child b", () -> "C");
    step.name("dynamic name " + a + b + c);
});

Create attachments as well as steps

step("get data", () -> {
    step("build client");
    List<String> responseData = step("run request", (step) -> {
        step.parameter("authorization", token);
        step.parameter("url", baseUrl);
        int[] requestBody = step.parameter("requestBody", new int[]{1, 2, 3});
        return getData(baseUrl, token, requestBody);
    });
    attachment("response", ObjectUtils.toString(responseData));
});