Compare .Kind() instead of direct equality checks on a dyn.Value

[shreyas-goenka]

Changes

This PR makes two changes:

1. In Track multiple locations associated with a dyn.Value #1510 we'll be adding multiple associated location metadata with a dyn.Value. The Go compiler does not allow comparing structs if they contain slice values (presumably due to multiple possible definitions for equality). In anticipation for adding a []dyn.Location type field to dyn.Value this PR removes all direct comparisons of dyn.Value and instead relies on the kind.

2. Retain location metadata for values in convert.FromTyped. The change diff is exactly the same as Retain location metadata for values in convert.FromTyped #1523. It's been combined with this PR because they both depend on each other to prevent test failures (forming a test failure deadlock).

Go patch used:

@@
var x expression
@@
-x == dyn.InvalidValue
+x.Kind() == dyn.KindInvalid

@@
var x expression
@@
-x != dyn.InvalidValue
+x.Kind() != dyn.KindInvalid

@@
var x expression
@@
-x == dyn.NilValue
+x.Kind() == dyn.KindNil

@@
var x expression
@@
-x != dyn.NilValue
+x.Kind() != dyn.KindNil

Tests

Unit tests and integration tests pass.