Support Isabelle code generation

[jonaskrask]

Related to issue #19

[jonaskrask]

Note: In progress on the server side

[nickbattle]

As above, the Server has been enhanced slightly to deal with "unknown" LSP method invocations. These are dispatched via a special RPC handler and directed to the (LSPX) workspace manager. The manager registers additional analysis plugins, as directed by a property called lspx.plugins, and the registry has a new method to identify any registered plugins that can process a given LSP method name. The plugin is then completely responsible for handling the new method - RPCRequest input; RPCResponse(s) output.

That said, the easiest way to integrate Leo's Isabelle translation is probably to add a new languageId to the existing "slsp/translate" method and use that to invoke the ISAPlugin. When the integration is more mature, we can introduce new LSP methods.

I think the "experimental" section of the "initialize" response should probably include a section that is generated by each loaded plugin. That way we add new features and communicate with the Client, without changing the "framework" on the Server.

[nickbattle]

The experimental section support above is now available in "development". For example, the CTPlugin now has a method like this:

	@Override
	public JSONObject getExperimentalOptions()
	{
		return new JSONObject("combinatorialTestProvider", new JSONObject("workDoneProgress", true));
	}

So when we know what options we want to add for Isabelle support, they can be added via the plugin, rather than by changing the Server itself.

[jonaskrask]

Do we want the options to be set at startup or should they be changeable between each invocation?

[nickbattle]

It's useful to allow plugins to set static capabilities. They can always send "registerCapability" messages themselves if we want it to be more dynamic?

[jonaskrask]

A button has been added for translate to Isabelle on the client side (development branch) with the language id: "isabelle"

[nickbattle]

Can you build the VSIX?

[jonaskrask]

Done, however the jars are not updated, so you will need to do that manually

[nickbattle]

Thanks. That's fine - jars I can handle :-)

[nickbattle]

Hmm... I've installed the 1.2.2 VSIX, but I'm not seeing any Isabelle options? :-( Is it supposed to be at the folder/project level or the per-file level? All I can see are the translate to LaTeX or Word options.

[nickbattle]

The good news is that it looks like the annotationPaths and JVMArguments settings give us the Java process settings that we need. So the folder settings.json is like this:

{
	"vdm-vscode.debug.experimentalServer": false,
	"vdm-vscode.highPrecision": false,
	"editor.codeLens": true,
	"vdm-vscode.annotationPaths": "/home/nick/.vscode/vdm2isa-4.4.4-SNAPSHOT-211019.jar",
	"vdm-vscode.JVMArguments": "-Dlspx.plugins=plugins.ISAPluginSL"
}

[jonaskrask]

is the server sending a translate to isabelle capability as with latex, word, etc.? If not, the button will not show

[nickbattle]

It's sending:

			"experimental": 
			{
				"translateProvider": 
				{
					"languageId": 
					[
						"latex",
						"word",
						"coverage",
						"graphviz",
						"isabelle"
					],
					"workDoneProgress": false
				},
				"dapServer": 
				{
					"port": 8001
				},
				"combinatorialTestProvider": 
				{
					"workDoneProgress": true
				},
				"proofObligationProvider": true
			}