[wasm][debugger] Add support for deref'ing pointers (#19760)
* [wasm][debugger] Send var names also, to `mono_wasm_get_variables`
- this will be useful in upcoming commits, which will need to use the
names for local pointer vars
* [wasm][debugger] Add support for deref'ing pointers
* [wasm][debugger] Dereference the pointer in js, instead of debugger.c
Based on suggestion from @vargaz
* [wasm][debugger][tests] Fix setting async methods when setting
.. breakpoint by method name. Async methods themselves don't have the
debug information. Instead, that can be found on the generated async
implementation type/method. Here, we just look for a type name
starting with `{original_type_name}/<{async_method_name}>`, and use the
method `MoveNext` from that.
* [wasm][debugger][tests] Update to set bp by method name+lineoffset
* Address review comments from Katelyn Gadd (@kg)
* Add test to check deref'ing invalid pointers
- We should really be handling invalid object ids, and report errors for
those, where appropriate. This will be done in a future PR
- For this PR, I'm adding tests that just check that invalid objects, or
trying to deref regular objects, doesn't blow up
* Remove old unused test code
* [wasm][debugger] Use JsonConvert instead of manually building the json string
- addresses review comment from @lewing