fix(deps): drop remark-gfm version (#2471)

# Submit a pull request

### 🎯 Goal

When user posts a specific message, the whole application crashes due to
[this issue](remarkjs/remark-gfm#57).

This PR lowers `remark-gfm` to a version that works well with the
current version of the `react-markdown` used within the SDK.

I won't be posting the breaking message in the PR for the obvious
reasons, message me if interested.

Author: arnautov-anton