879: Fixes to goto definition r=vipentti a=vipentti
Previously goto definition would fail when the cursor was over the name of the definition. Now we should properly resolve to a `NavigationTarget` when on top of the name of a definition.
In addition this adds `name_range` field to `FileSymbol`, this further fixes goto_definition and symbol based navigation by allowing the `NavigationTarget` to actually have a `focus_range`, meaning instead of focusing on the start of the `full_range`, we can have the cursor focus on the name.
e.g. goto definition
```rust
fn bar() {
fn foo() { }
foo<|>();
}
```
Previously this would put the cursor at the start of the FN_DEF:
```rust
fn bar() {
<|>fn foo() { }
foo();
}
```
Now when using the symbol based resolving, we'll have a proper focus range and instead put the cursor at the start of the name.
```rust
fn bar() {
fn <|>foo() { }
foo();
}
```
This fixes#877 but doesn't contain the refactoring of the return type for `goto_definition`
Co-authored-by: Ville Penttinen <villem.penttinen@gmail.com>
e5fb33a946