Add missing initialization for `applications` and `exports` in reclass-rs backend

[simu]

This is a follow-up for #1059 and #1142. We forgot to include the fix in #1142 in #1059.

Proposed Changes

• Fix incorrect default initializer for exports field of target
• Set applications and exports in reclass-rs backend
• Run Kubernetes compile tests with reclass-rs

Docs and Tests

• [x] Tests added
• [ ] Updated documentation