make blockscout the default block explorer

[divine-comedian]

At the request of one of our partners - blockscout - we should change the default block explorer of the app to use blockscout for EVM chains we support

this includes:

• donation table tx links
• recurring donation table tx links
• givfarm interactions
• givpower interactions
• givstream interactions
• user address on user profile pages external link
• donation success page tx links

PR was introduced by member of blockscout team but it has some merge conflicts and I'm not sure this will actually work inside our codebase
#4206

Production URLs

• OPTIMISM https://optimism.blockscout.com/
• BASE https://base.blockscout.com/
• CELO https://celo.blockscout.com/
• ARBITRUM https://arbitrum.blockscout.com/
• MAINNET https://eth.blockscout.com/
• POLYGON https://polygon.blockscout.com/
• POLYGON ZKEVM https://zkevm.blockscout.com/
• GNOSIS https://gnosis.blockscout.com/
• ETH CLASSIC https://etc.blockscout.com/

staging URLs

• ARB SEPOLIA https://arbitrum-sepolia.blockscout.com/
• MAINNET SEPOLIA https://eth-sepolia.blockscout.com/
• OP SEPOLIA https://optimism-sepolia.blockscout.com/
• BASE SEPOLIA https://base-sepolia.blockscout.com/
• ETH CLASSIC MORDOR https://etc-mordor.blockscout.com/
• CELO ALFAJORES https://celo-alfajores.blockscout.com/
• POLYGON ZKEVM CARDONA https://explorer-ui.cardona.zkevm-rpc.com/
• GNOSIS https://gnosis.blockscout.com/
• POLYGON https://polygon.blockscout.com/