Add eslint rule to forbid importing public code from server code

[joshdover]

Similar to #49053, we could add a lint rule to make sure that client-side code is not imported into server-side code.

While not as critical as #49053, this could prevent attempting to use code that depends on Browser APIs in the Node environment.

One snag here is that when we have both the rules added in #49053 and this, we will not be able to share any code across plugins without also formalizing the "common" directory pattern which specifies code that is safe for both environments.

[elasticmachine]

Pinging @elastic/kibana-platform (Team:Platform)