Fix LocalAddr creation in target collection for JSON files

[dbanck]

Sometimes, we create local addresses with nil steps, and the LS crashes when iterating over those. This PR aims to fix that.

We don't get a body range for JSON-based configuration files, so we can never set the TargetableFromRangePtr for collected targets.

hcl-lang/decoder/reference_targets.go

Lines 687 to 689 in 4804a1c

	if bAddrSchema.DependentBodySelfRef && content.RangePtr != nil && selfRefBodyRangePtr == nil {
	selfRefBodyRangePtr = content.RangePtr
	}

Without this pointer, we can't build a local address. So instead of trying to be clever and set a specific length, we now create all local addresses with a zero length.

Fixes hashicorp/vscode-terraform#1338
Fixes hashicorp/terraform-ls#1157

[radeksimko]

The crash was related to a different PR which I had accidentally checked out and forgot about https://github.com/hashicorp/terraform-schema/pull/174/files

it causes the crash on main as well, so it doesn't seem affected by this PR.

---

One more thing I forgot to mention in my previous review is that if it makes things easier, we could gate LocalAddr setting on hclsyntax / JSON, since we won't ever need local addresses inside JSON anyway, since we don't do completion inside JSON files anyway.

[dbanck]

I think gating LocalAddr wouldn't make the code considerably easier to read, so I would keep it as is. Happy to revisit this in the future.