[pallet-revive] move exec tests (#7590)

Moving exec tests into a new file

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Co-authored-by: cmd[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Alexander Theißen <alex.theissen@me.com>

prdoc/pr_7590.prdoc

+title: '[pallet-revive] move exec tests'
+doc:
+- audience: Runtime Dev
+  description: Moving exec tests into a new file
+crates:
+- name: pallet-revive
+  bump: minor