* intern_pool: add getUnsignedInt
* add an empty struct literal
* resolve array length as usize in comptime interpreter
* use only one global intern pool
* store analysis errors in `DocumentStore.Handle`
* add typed undefined value
* add typed null value
* move language feature files into separate folder
* move code completions into features/completions.zig
* move goto definition/declaration into features folder
* move hover into features folder
* restructure imports
* move selection range into features folder
* restructure request handling tracy call
* add missing features to `zls.zig`