Various improvements

[FnControlOption]

Show type when hovering over block label

Resolve type of implicitly void variant of tagged union

Fix semantic highlighting for MyEnum.value/MyTaggedUnion.value

Before

const E = enum { foo, bar };
const U = union(E) { foo: f32, bar: void };

const std = @import("std");
pub fn main() !void {
    const efoo = E.foo;
    const ufoo = U.foo;
    const bar = @as(U, U.bar);
    std.debug.print("{}\n{}\n{}\n", .{
        @TypeOf(efoo), // => E
        @TypeOf(ufoo), // => E
        @TypeOf(bar), // => U
    });
}

Resolve type of enum literal in container field init

Preserve whitespace in doc comments

Before

Highlight entire identifier on hover/goto

Before

Fix symbol lookup for var with same name as field and vice versa

Before

Add hover for MyEnum.value/MyTaggedUnion.value

Fix type resolution for MyTaggedUnion.value

const Foo = union(enum) {
    bar,
    const baz: i32 = 123;
};

const foobar = Foo.bar; // @typeInfo(Foo).Union.tag_type.?
const foobaz = Foo.baz; // i32

const std = @import("std");
pub fn main() !void {
    std.debug.print("{}\n", .{@TypeOf(foobar)});
}