feat(devcontainer): add devcontainer

[martinhaintz]

I tried building the sentry-javascript repo locally but had multiple dependency issues. Therefore I created a devcontainer, which includes all needed dependencies.

In the Dockerfile are now also all needed dependencies shown.

As written in the contribution guide you only have to run yarn which installs the dependencies and with yarn build to start the build.

At the moment the docker image is built locally, but in the future, it can be built in the ci and provided by the GitHub container registry.

I tested it on my MacBook Air M1.