Add hover info for individual clause

[BinderDavid]

Just an uninformative "Clause" for now. I also want to add hover information for patterns, but they currently lack spans.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 12 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
lang/driver/src/info/collect.rs	0.00%	5 Missing ⚠️
lang/lsp/src/hover.rs	0.00%	4 Missing ⚠️
lang/driver/src/info/data.rs	0.00%	3 Missing ⚠️

Files with missing lines	Coverage Δ
lang/driver/src/info/data.rs	0.00% <0.00%> (ø)
lang/lsp/src/hover.rs	0.00% <0.00%> (ø)
lang/driver/src/info/collect.rs	0.00% <0.00%> (ø)

... and 1 file with indirect coverage changes