Rebranding: Update Backend URLs in Explorer

[alfetopito]

Description

Update URLs used on explorer to talk to backend api:

gp-ui/webpack.config.js

Lines 28 to 33 in 6620910

	OPERATOR_URL_STAGING_MAINNET: 'https://protocol-mainnet.dev.gnosisdev.com/api',
	OPERATOR_URL_STAGING_RINKEBY: 'https://protocol-rinkeby.dev.gnosisdev.com/api',
	OPERATOR_URL_STAGING_XDAI: 'https://protocol-xdai.dev.gnosisdev.com/api',
	OPERATOR_URL_PROD_MAINNET: 'https://protocol-mainnet.gnosis.io/api',
	OPERATOR_URL_PROD_RINKEBY: 'https://protocol-rinkeby.gnosis.io/api',
	OPERATOR_URL_PROD_XDAI: 'https://protocol-xdai.gnosis.io/api',

Proposal

Prod urls per network:

• api.cow.fi/mainnet
• api.cow.fi/rinkeby
• api.cow.fi/xdai

*Staging urls per networks:

• barn.api.cow.fi/mainnet
• barn.api.cow.fi/rinkeby
• barn.api.cow.fi/xdai

*Still needs to confirm this will be the final domain

Additional context
Add any other context or screenshots about the feature request here.

[alfetopito]

Point the PR to a new branch called rebranding when ready (create the branch from develop if it doesn't exist yet)

[alongoni]

Point the PR to a new branch called rebranding when ready (create the branch from develop if it doesn't exist yet)

I've created the rebranding branch

[elena-zh]

I have created a separate task for not implemented changes related to updating staging URLs #944