Migrate from MITyCLib to xades4j

[xprl-gjf]

Rework xades-firma to use xades4j in place of MITyCLib.
This removes the need to package the MITyCLib libraries as a shadow jar, since xades4j is available via maven central repo.

[xprl-gjf]

Sadly, testing against the SRI pruebas ambiente rejects facturas signed with this version of the library.

Attached are versions of a factura signed using the previous MITyCLib implementation, and also with this xades4j implementation.

The xades4j version can be sent to SRI via 'enviar' web-service. But a subsequent attempt to authorize the factura via 'autorizar' web service results in:

{"mensaje":[{"identificador":"39","mensaje":"FIRMA INVALIDA","informacionAdicional":"La firma es invalida [Firma inválida. El certificado firmante no es válido.]","tipo":"ERROR"}]}

Requires further investigation to resolve.
factura_27922910115.MITyCLib.xml.txt
factura_27922910115.xades4j.xml.txt

[xprl-gjf]

Suspicion falls on the SRI validation service (which we know uses MITyCLib) not handling the '
' line ending characters correctly...

[xprl-gjf]

Some related discussion, without resolution, at xades4j #259

[xprl-gjf]

Following up on &13#; line-endings, see issues such as:
https://bugs.openjdk.org/browse/JDK-8264194
eclipse-ee4j/metro-jax-ws#93 (comment)

[xprl-gjf]

Following commit 9d6df9a, signatures are added without any line breaks (and therefore no 
 chars in the certificate. See example attached.

Still rejected by SRI:

{"mensaje":[{"identificador":"39","mensaje":"FIRMA INVALIDA","informacionAdicional":"La firma es invalida [Firma inválida. El certificado firmante no es válido.]","tipo":"ERROR"}]}

So, line breaks are probably not the source of the problem... :(

factura_27922910115.xades4j_3.xml.txt