feat: implement and calculate the current key period using pallas #113

Job	Run time
build (macos-12)	4m 3s
build-open-api-ui	7s
build (windows-latest)	4m 10s
build-docusaurus	1m 58s
build-test-wasm	2m 46s
build-ubuntu-X64	4m 48s
cargo-doc	1m 7s
check	1m 6s
test (ubuntu-22.04)	5m 44s
test (macos-12)	2m 1s
test (windows-latest)	5m 27s
build-test-explorer	1m 8s
publish-wasm-test (mithril-client-wasm)	1m 15s
publish-docs	0s
e2e (std, thales, 8.7.3, 0, #1)	1m 11s
e2e (std, thales, 8.7.3, 0, #2)	1m 11s
e2e (std, thales, 8.7.3, 10, #1)	1m 9s
e2e (std, thales, 8.7.3, 10, #2)	1m 9s
e2e (std, thales, 8.7.3, 100, #1)	1m 16s
e2e (std, thales, 8.7.3, 100, #2)	1m 13s
e2e (std, thales, 8.1.2, 100, #1)	1m 7s
e2e (p2p, thales, 8.7.3, 100, #1, --use-p2p-network)	1m 8s
publish-tests-results	15s
publish-crate-test	0s
unstable-release	0s
docker-mithril	0s
deploy-testing	0s
	45m 19s

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