Breaking change: Rename `core` crate to `kernel`

Due to https://github.com/JelteF/derive_more/issues/180, core have to be renamed.

changed milestone to %Alpha release

assigned to @v-lafeychine

created branch 13-breaking-change-rename-core-crate-to-kernel to address this issue

mentioned in merge request !14 (merged)

closed with merge request !14 (merged)

closed with commit 828cb706

changed the incident status to Resolved by closing the incident

changed the incident status to Resolved by closing the incident

mentioned in commit 828cb706

mentioned in commit b6f52296

mentioned in commit 2dcd5f5c

mentioned in commit 8407d162