Retrieve Blockchain logs

[m-Peter]

Work towards: onflow/developer-grants#148
Companion PR: onflow/cadence#2505 ✔️

Description

Provides a way to retrieve logs from the Blockchain, programmatically, from the testing framework, with:

import Test

pub let blockchain = Test.newEmulatorBlockchain()

blockchain.logs()

Also improves the look & feel for logs that come from test files. E.g:

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• Targeted PR against master branch
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work
• Code follows the standards mentioned here
• Updated relevant documentation
• Re-reviewed Files changed in the Github PR explorer
• Added appropriate labels

[m-Peter]

Logs from test files are consistent with the blockchain logs. The INF logs are the blockchain logs, which we could return to the test file

[SupunS]

Looks good so far!

[turbolent]

Nice! 👌