feat: render suggestions in MR reviews

This MR improves the rendering of suggestions in the MR review.

This comment:

Adding a line12

```suggestion:-1+0
function containingFunctionABCD(): void{
    function subFunctionDEF(): void{
```

And here

Get's rendered as

The new suggestion rendering can't be on feature-parity with the web version, because we don't have access to the same data through API. I created an issue for that: gitlab#347504

We only show the suggested lines, not a full diff. And we also can't apply the suggestion from the comment. I added a link to open the comment on the web.

	web	before	after
single suggestion
multiple suggestions

Editing suggestion:

editing-suggestion

Related to #371 (closed)