Display contract names in UI #1775

Job	Run time
Build Echidna on ubuntu-20.04	3m 33s
Build Echidna on macos-latest	3m 23s
Build Echidna on windows-latest	10m 39s
Test with solc 0.4.25 on ubuntu-latest	3m 12s
Test with solc 0.5.7 on ubuntu-latest	3m 31s
Test with solc 0.6.12 on ubuntu-latest	3m 30s
Test with solc 0.7.5 on ubuntu-latest	3m 59s
Test with solc 0.4.25 on windows-latest	4m 26s
Test with solc 0.5.7 on windows-latest	4m 49s
Test with solc 0.6.12 on windows-latest	5m 56s
Test with solc 0.7.5 on windows-latest	6m 18s
	53m 16s

Provide feedback