Update to LSP4J 0.13.0 / LSP 3.17.0

[cdietrich]

[cdietrich]

looks like now some changes are coming in

[cdietrich]

TODO: Change WorkspaceSymbol/DocumentSymvol Service to use WorkspaceSymbols/DocumentSymbols instead of SymbolInformation

[cdietrich]

wip branch is https://github.com/eclipse/xtext-core/tree/cd_lsp4j0130

[cdietrich]

timeline for protocol 3.17 unclear

[cdietrich]

3.17 was published today.
complete changelog
https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#version_3_17_0

lsp4j has no eta yet eclipse-lsp4j/lsp4j#541

[cdietrich]

@rubenporras can you do some contributions here?