Providing wallet with a `blockExporerUrl` could be valuable given that applications can permissionessly interface with each other given that standards are followed and become interoperable.
Hence I've explored existing block explorers and identified existing patterns where these endpoints are in consensus and could be specified under a standard which this EIP describes
### L1 Blockchain Explorers
#### Blocks
Blockscout (chainId=100) -> https://blockscout.com/poa/xdai/blocks/<BLOCK_HASH_OR_HEIGHT>
Etherscan (chainId=1) -> https://etherscan.io/block/<BLOCK_HASH_OR_HEIGHT>
Etherchain (chainId=1) -> https://etherchain.org/block/<BLOCK_HASH_OR_HEIGHT>
Ethplorer (chainId=1) -> unsupported
Etherscan and Etherchain are in consensus for blocks endpoint but Blockscout uses `/blocks` endpoint instead and Ethplorer doesn't have a page for blocks so returns 404 not found.
#### Transactions
Blockscout (chainId=100) -> https://blockscout.com/poa/xdai/tx/<TX_HASH>
Etherscan (chainId=1) -> https://etherscan.io/tx/<TX_HASH>
Etherchain (chainId=1) -> https://etherchain.org/tx/<TX_HASH>
Ethplorer (chainId=1) -> https://ethplorer.io/tx/<TX_HASH>
All block explorers are in consensus for transactions endpoint.
#### Accounts
Blockscout (chainId=100) -> https://blockscout.com/poa/xdai/address/<ACCOUNT_ADDRESS>
Etherscan (chainId=1) -> https://etherscan.io/address/<ACCOUNT_ADDRESS>
Etherchain (chainId=1) -> https://etherchain.org/account/<ACCOUNT_ADDRESS>
Ethplorer (chainId=1) -> https://ethplorer.io/address/<ACCOUNT_ADDRESS>
All block explorers are in consensus for accounts endpoint except Etherchain which uses `/account` endpoint instead
#### ERC-20 Tokens
Blockscout (chainId=100) -> https://blockscout.com/poa/xdai/tokens/<TOKEN_ADDRESS>
Etherscan (chainId=1) -> https://etherscan.io/token/<TOKEN_ADDRESS>
Etherchain (chainId=1) -> https://etherchain.org/token/<TOKEN_ADDRESS>
Ethplorer (chainId=1) -> https://ethplorer.io/address/<TOKEN_ADDRESS>
Etherscan and Etherchain are in consensus but Blockscout uses `/tokens` endpoint instead and Ethplorer doesn't have a page for tokens so redirects to accounts page (`/address`).
### L2 Explorers
#### Blocks
Matic -> https://explorer.matic.network/blocks/<BLOCK_HEIGHT_OR_HASH>
zkScan -> https://zkscan.io/blocks/<BLOCK_NUMBER>
Fuel -> https://rinkeby.fuel.sh/block/<BLOCK_NUMBER>
#### Transactions
Matic -> https://explorer.matic.network/tx/<TX_HASH>
zkScan -> https://zkscan.io/transactions/<TX_HASH>
Fuel -> https://rinkeby.fuel.sh/tx/<TX_HASH>
#### Accounts
Matic -> https://explorer.matic.network/address/<ACCOUNT_ADDRESS>
zkScan -> https://zkscan.io/accounts/<ACCOUNT_ADDRESS>
Fuel -> https://rinkeby.fuel.sh/address/<ACCOUNT_ADDRESS>
#### ERC-20 Tokens
Matic -> https://explorer.matic.network/tokens/<TOKEN_ADDRESS>
zkScan -> unsupported (`/tokens` displays a list of tokens pointing to L1 explorer)
Fuel -> unsupported
## EIP-3091
### Blocks
<BLOCK_EXPORER_URL>/block/<BLOCK_HASH_OR_HEIGHT>
### Transactions
<BLOCK_EXPORER_URL>/tx/<TX_HASH>
### Accounts
<BLOCK_EXPORER_URL>/address/<ACCOUNT_ADDRESS>
### ERC-20 Tokens
<BLOCK_EXPORER_URL>/token/<TOKEN_ADDRESS>
