Add an `era` subcommand to create keypair #8179

All 1 591 tests pass in 10m 22s

4 files ±0 56 suites ±0 10m 22s ⏱️ -2s
1 591 tests ±0 1 591 ✅ ±0 0 💤 ±0 0 ❌ ±0
1 889 runs ±0 1 889 ✅ ±0 0 💤 ±0 0 ❌ ±0

Results for commit 257cb8f. ± Comparison against earlier commit f998fe7.