Add events sending and sent to tx submission, add arg latestBlockHash to event confirmation

[ryanio]

This PR:

1. Adds events to the send tx promievent: sending and sent.
2. Adds third arg to confirmation: latestBlockHash.

Fixes #3438

Type of change

• New feature (non-breaking change which adds functionality)

Checklist:

• I have selected the correct base branch.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• Any dependent changes have been merged and published in downstream modules.
• I ran npm run dtslint with success and extended the tests and types if necessary.
• I ran npm run test:unit with success.
• I ran npm run test:cov and my test cases cover all the lines and branches of the added code.
• I ran npm run build-all and tested the resulting files from dist folder in a browser.
• I have updated the CHANGELOG.md file in the root folder.
• I have tested my code on the live network.

[coveralls]

Coverage increased (+0.04%) to 89.779% when pulling 3cef72c on issue/3438 into 3107c98 on 1.x.

[cgewecke]

This is super cool! Just left a couple questions.

[cgewecke]

This looks perfect to me 🎉

The payload object seems good. The formatting's raw which is good for seeing what actually gets sent over the wire.

An example from the deploy test:

{
 "method": "eth_sendTransaction",
 "params": [
  {
   "from": "0x4f861a99cf97d053ccb97f9fd5acd5ce2f570171",
   "data": "0x6080604.....",
   "gasPrice": "0x1",
   "gas": "0x3d0900"
  }
 ]
}

[cgewecke]

👍 Nice catch.

[ryanio]

great, thanks!