Nested exception support

[konraddysput]

Why

This pull request captures nested exception via UncaughtExceptionHandler. In the past, the SDK allowed only capturing a single exception, even if the exception had a cause. This pull request converts an exception chain into a report array with additional attribute identifiers, so the user can see the whole nested exception history.

Example:

 public void unhandledException(View view) throws IOException {
        try {
            getSaveData();
        } catch (IOException exception) {
            this.throwOriginalExceptionAsInnerException(exception);
        }
    }

    private void throwOriginalExceptionAsInnerException(Exception exception) throws IOException {
        throw new IOException("test", exception);
    }

ref: BT-5223

[melekr]

lgtm

[BartoszLitwiniuk]

Are you sure that we should mix changing exception to throwable with adding new feature?

[BartoszLitwiniuk]

lgtm! Good job @konraddysput