Add `mithril-client-wasm` tests in multi platform test #5196

All 784 tests pass in 8m 58s

3 files ±0 33 suites ±0 8m 58s ⏱️ +12s
784 tests ±0 784 ✅ ±0 0 💤 ±0 0 ❌ ±0
857 runs ±0 857 ✅ ±0 0 💤 ±0 0 ❌ ±0

Results for commit a0c70cb. ± Comparison against earlier commit f849737.