Extend onHover with symbol information

[skovhus]

When hovering over a word we have different strategies for providing documentation (explainshell, man pages, help), but we could also provide information about symbols (i.e. variables and functions).

There are at least two cases:

• symbols defined inside the file (not sure if we should do anything here)
• symbols defined outside the file / in the workspace (we could copy the behavior for when auto-completing "Function defined in ../some-file.sh")

https://github.com/bash-lsp/bash-language-server/blob/master/server/src/server.ts#L183

[skovhus]

This was released as bash-language-server@1.14.0.