Add symbol tags as proposed for LSP specification (e.g. visibility tags, static, abstract, etc.) #977

[travkin79]

Start using new symbol tags as proposed in my microsoft/language-server-protocol#2003, for example, adding private, package, protected, and public visibility tags as well as tags like static, final, abstract, read-only, nullable and non-null. Our motivation comes from our wish to add visibility and other symbol details to the outline view (see discussion #977), but maybe also to the call hierarchy and to the type hierarchy or to other related features / LSP operations.

The PR on the LSP specification requires at least one implementation in a language server and / or a client. We plan to finish a first language server implementation in clangd [1] [2] and a first client implementation in LSP4J, LSP4E, and CDT LSP (which is using clangd).

See microsoft/language-server-protocol#2003
and llvm/llvm-project#113669
and eclipse-lsp4j/lsp4j#856

[rubenporras]

This would be great it the LSP gets improved and a new version in released.