Make ERC1155 uri() function public instead external

[peak3d]

uri() function in ERC1155.sol is declared external and subclasses overriding uri() cannot call super.uri().

💻 Environment

hardhat

📝 Details

When overwriting uri() implemented here:

https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC1155/ERC1155.sol#L58

it is not possible to call super.uri() because of the external "modifier". uri() is the only way to access the _uri private member in ERC1155.sol which is set in ctor.

🔢 Code to reproduce bug

contract test is ERC1155 {
function uri(uint256 tokenId) external view virtual override returns (string memory) {
// return URI for special cases
//fallback:
return super.uri(). <- compilation failed because uri() can only be called from external
}