Feature #1593: Support promise-based api of Safe Apps SDK

[mmv08]

This PR:

• Adds support for v1 SDK with promise-based API in a backward-compatible manner (sdk v0.x is still supported)
• Adds a communicator which is responsible for handling App's requests
• Add incremental builds for pre-push to speed it up

An app for testing can be found here: https://github.com/gnosis/safe-test-app/tree/sdk/v2

[github-actions]

CLA Assistant Lite All Contributors have signed the CLA.

[github-actions]

ESLint Summary View Full Report

Annotations are provided inline on the Files Changed tab. You can also see all annotations that were generated on the annotations page.

Type	Occurrences	Fixable
Errors	0	0
Warnings	0	0
Ignored	0	N/A

• Result: ✅ success
• Annotations: 0 total

---

^{Report generated by eslint-plus-action}

[ghost]

Travis automatic deployment:
https://pr1594--safereact.review.gnosisdev.com/rinkeby/app

[ghost]

Travis automatic deployment:
https://pr1594--safereact.review.gnosisdev.com/volta/app

[ghost]

Travis automatic deployment:
https://pr1594--safereact.review.gnosisdev.com/rinkeby/app

[ghost]

Travis automatic deployment:
https://pr1594--safereact.review.gnosisdev.com/volta/app

[github-actions]

ESLint Summary View Full Report

Annotations are provided inline on the Files Changed tab. You can also see all annotations that were generated on the annotations page.

Type	Occurrences	Fixable
Errors	0	0
Warnings	0	0
Ignored	0	N/A

• Result: ✅ success
• Annotations: 0 total

---

^{Report generated by eslint-plus-action}

[ghost]

Travis automatic deployment:
https://pr1594--safereact.review.gnosisdev.com/rinkeby/app

[ghost]

Travis automatic deployment:
https://pr1594--safereact.review.gnosisdev.com/volta/app

[ghost]

Travis automatic deployment:
https://pr1594--safereact.review.gnosisdev.com/volta/app

[ghost]

Travis automatic deployment:
https://pr1594--safereact.review.gnosisdev.com/rinkeby/app

[ghost]

Travis automatic deployment:
https://pr1594--safereact.review.gnosisdev.com/rinkeby/app

[ghost]

Travis automatic deployment:
https://pr1594--safereact.review.gnosisdev.com/volta/app

[ghost]

Travis automatic deployment:
https://pr1594--safereact.review.gnosisdev.com/rinkeby/app

[dasanra]

@francovenica to test this PR you can use the app provided in the description. This app uses the new features of apps SDK. You can also check that current Rinkeby apps still work as expected

[ghost]

Travis automatic deployment:
https://pr1594--safereact.review.gnosisdev.com/volta/app

[dasanra]

@francovenica you can use this deployed app to test the new functionalities of SDK

https://ipfs.io/ipfs/QmfMq8NgxdDfai1qKv7bGbT8DegYX4mNzmpi9AkY1VJZBS

[francovenica]

I added the app using the URL Dani provided and it worked, but I had to refresh the page since adding it just show the loading icon forever (waited 20 mins till I refreshed manually to actually see the app)

It seems the app create just test tx that do nothing of real effect, so I don't think the app itself requires any testing or validations, still I played with the amount of gas for the tx, and even putting a low number like "1000" and not getting the "Gas estimation is OK" sign the tx went through and it was mined just fine.
A tx in volta: https://volta-explorer.energyweb.org/tx/0x5c00c154b84664c0687f6a94603517b7d4db2c7e21662e681d4590134b0d4325/internal-transactions
Volta safe used: 0x538622a690A651D852277c07334dC3377E22cdeF

Tx in rinkeby: https://rinkeby.etherscan.io/tx/0xe4f86cfaabacedc0096c492d6671b68341008c72e3e424dbafa4d7d7b8b03fa1
rinkeby safe use: 0x9913B9180C20C6b0F21B6480c84422F6ebc4B808

I tried in Rinkeby other apps: Compound, idle, sablier. With WC I tested just the connection with the "Wallet connect example" page

It looks good for me

[ghost]

Travis automatic deployment:
https://pr1594--safereact.review.gnosisdev.com/rinkeby/app

[ghost]

Travis automatic deployment:
https://pr1594--safereact.review.gnosisdev.com/volta/app