add support for websocket urps available >= LibreOffice 24.2

[caolanm]

a new option alongside "pipe" and "socket" to communicate with a Collabora Online server configured to accept uno over websocket.

urp syntax is:
uno:websocket,url=

in comparison with preexisting
[uno:]socket,host=,port=
[uno:]pipe,name=

Implemented in Collabora Online with CollaboraOnline/online#6992 and supported by LibreOffice 24.2 jars with https://gerrit.libreoffice.org/c/core/+/151171

not to be confused with jodconverter's existing "remote" mode which is for collabora-online wrt to the convert-to api connection point. While "external" is the traditional socket mode which this is most similar to.

[sbraconnier]

Thanks a lot for your contribution, I'll merge it somewhere this week for sure.

[caolanm]

anything else I need to do here? I'm assuming the ci failures are unrelated

[sbraconnier]

@caolanm

Could you please add a comment with a brief text explaining this new feature so I could update the configuration documentation

[caolanm]

Here's what my sample code looks like to use this with a local collabora online instance running on port 9980 on localhost

ExternalOfficeManager.Builder config = ExternalOfficeManager.builder();
String wopiURI = "http://localhost:9980/wopi/files/some-sample-document.odt";
String encodedURI = URLEncoder.encode(wopiURI, StandardCharsets.UTF_8);
ExternalOfficeManager officeManager = config.websocketUrls("ws://localhost:9980/cool/" + encodedURI + "/ws").build();
officeManager.start();

And then its the same as any ExternalOfficeManager case after that. Requires the LibreOffice jars from >= 24.02 or Collabora jars from >= 23.05 and a >= 23.05 Collabora Online with "enable_websocket_urp" set to true in its coolwsd.xml where that is documented inline as "Should we enable URP (UNO remote protocol) communication over the websocket"