prefix I to EIP interfaces and move to eip/interface

Author: Krishang Nadgauda

contracts/eip/ERC1155.sol renamed to contracts/eip/interface/IERC1155.sol

@@ -6,7 +6,7 @@ pragma solidity ^0.8.0;
     @dev See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-1155.md
     Note: The ERC-165 identifier for this interface is 0xd9b67a26.
  */
-interface ERC1155 {
+interface IERC1155 {
     /**
         @dev Either `TransferSingle` or `TransferBatch` MUST emit when tokens are transferred, including zero value transfers as well as minting or burning (see "Safe Transfer Rules" section of the standard).
         The `_operator` argument MUST be msg.sender.

contracts/eip/ERC1155Enumerable.sol renamed to contracts/eip/interface/IERC1155Enumerable.sol

@@ -3,7 +3,7 @@ pragma solidity ^0.8.0;
 
 /// @title ERC1155 Non-Fungible Token Standard, optional enumeration extension
 /// @dev See https://eips.ethereum.org/EIPS/eip-1155
-interface ERC1155Enumerable {
+interface IERC1155Enumerable {
     /// @notice Returns the next token ID available for minting
     /// @return The token identifier for the `_index`th NFT,
     ///  (sort order not specified)

contracts/eip/ERC1155Metadata.sol renamed to contracts/eip/interface/IERC1155Metadata.sol

@@ -4,7 +4,7 @@ pragma solidity ^0.8.0;
 /**
     Note: The ERC-165 identifier for this interface is 0x0e89341c.
 */
-interface ERC1155Metadata {
+interface IERC1155Metadata {
     /**
         @notice A distinct Uniform Resource Identifier (URI) for a given token.
         @dev URIs are defined in RFC 3986.

contracts/eip/ERC1155Supply.sol renamed to contracts/eip/interface/IERC1155Supply.sol

@@ -3,7 +3,7 @@ pragma solidity ^0.8.0;
 
 /// @title ERC1155S Non-Fungible Token Standard, optional supply extension
 /// @dev See https://eips.ethereum.org/EIPS/eip-1155
-interface ERC1155Supply {
+interface IERC1155Supply {
     /// @notice Count NFTs tracked by this contract
     /// @return A count of valid NFTs tracked by this contract, where each one of
     ///  them has an assigned and queryable owner not equal to the zero address

contracts/eip/ERC20.sol renamed to contracts/eip/interface/IERC20.sol

@@ -5,7 +5,7 @@ pragma solidity ^0.8.0;
  * @title ERC20 interface
  * @dev see https://github.com/ethereum/EIPs/issues/20
  */
-interface ERC20 {
+interface IERC20 {
     function totalSupply() external view returns (uint256);
 
     function balanceOf(address who) external view returns (uint256);

contracts/eip/ERC20Metadata.sol renamed to contracts/eip/interface/IERC20Metadata.sol

@@ -5,7 +5,7 @@ pragma solidity ^0.8.0;
  * @title ERC20Metadata interface
  * @dev see https://github.com/ethereum/EIPs/issues/20
  */
-interface ERC20Metadata {
+interface IERC20Metadata {
     function name() external view returns (string memory);
 
     function symbol() external view returns (string memory);

contracts/eip/ERC721.sol renamed to contracts/eip/interface/IERC721.sol

@@ -5,7 +5,7 @@ pragma solidity ^0.8.0;
 /// @dev See https://eips.ethereum.org/EIPS/eip-721
 ///  Note: the ERC-165 identifier for this interface is 0x80ac58cd.
 /* is ERC165 */
-interface ERC721 {
+interface IERC721 {
     /// @dev This emits when ownership of any NFT changes by any mechanism.
     ///  This event emits when NFTs are created (`from` == 0) and destroyed
     ///  (`to` == 0). Exception: during contract creation, any number of NFTs

contracts/eip/ERC721Enumerable.sol renamed to contracts/eip/interface/IERC721Enumerable.sol

@@ -5,7 +5,7 @@ pragma solidity ^0.8.0;
 /// @dev See https://eips.ethereum.org/EIPS/eip-721
 ///  Note: the ERC-165 identifier for this interface is 0x780e9d63.
 /* is ERC721 */
-interface ERC721Enumerable {
+interface IERC721Enumerable {
     /// @notice Enumerate valid NFTs
     /// @dev Throws if `_index` >= `totalSupply()`.
     /// @param _index A counter less than `totalSupply()`

contracts/eip/ERC721Metadata.sol renamed to contracts/eip/interface/IERC721Metadata.sol

@@ -5,7 +5,7 @@ pragma solidity ^0.8.0;
 /// @dev See https://eips.ethereum.org/EIPS/eip-721
 ///  Note: the ERC-165 identifier for this interface is 0x5b5e139f.
 /* is ERC721 */
-interface ERC721Metadata {
+interface IERC721Metadata {
     /// @notice A descriptive name for a collection of NFTs in this contract
     function name() external view returns (string memory);
 

contracts/eip/ERC721Supply.sol renamed to contracts/eip/interface/IERC721Supply.sol

@@ -5,7 +5,7 @@ pragma solidity ^0.8.0;
 /// @dev See https://eips.ethereum.org/EIPS/eip-721
 ///  Note: the ERC-165 identifier for this interface is 0x780e9d63.
 /* is ERC721 */
-interface ERC721Supply {
+interface IERC721Supply {
     /// @notice Count NFTs tracked by this contract
     /// @return A count of valid NFTs tracked by this contract, where each one of
     ///  them has an assigned and queryable owner not equal to the zero address