Set LANG and LOCALE_ARCHIVE for nix shell

[mkoura]

Set correct locale env variables in nix so cardano-cli ran from nix-shell works as expected.

Without proper locale settings, e.g. multi-assets with unicode chars in asset name don't work:

$ cardano-cli transaction build-raw --fee 0 --out-file test_minting_unicode_asset_name_mint_estimate_tx.body --tx-in 2eaa1408eb5a4388ffa82d2c3f378dc2edb7c471a44ccfdf6bfeea4b54d0e858#0 --tx-out "addr_test1vzazmulffx974jaxjn3kv76kdew4kxr99tw4v5kad50xq7sfjytzv+900000000+5 7c7861c4b99224819818b335eb61c97e3bbec777aece7f1563d920bf.ěůřščžďťňkszw" --mint "5 7c7861c4b99224819818b335eb61c97e3bbec777aece7f1563d920bf.ěůřščžďťňkszw" --minting-script-file test_minting_unicode_asset_name.script
option --tx-out: 
           unexpected "\56516"
           expecting alphanumeric asset name
...

With correct locale there's no issue:

$ cardano-cli transaction build-raw --fee 191769 --out-file test_minting_unicode_asset_name_mint_tx.body --tx-in ff6a1d797d27e4408a293e5b2985556095afc8a28686e0d6ae403af962093098#0 --tx-out "addr_test1vrktl4mg8w83dl8untnmn99maz4yz4sjkk8m5jqay0xzgfq9jwrw6+899808231+5 e48c26399203edda32b52d52fd7c4d3566f350a037efbff00aedf883.ěůřščžďťňdxjk" --mint "5 e48c26399203edda32b52d52fd7c4d3566f350a037efbff00aedf883.ěůřščžďťňdxjk" --minting-script-file test_minting_unicode_asset_name.script

$ cardano-cli query utxo --address addr_test1vrktl4mg8w83dl8untnmn99maz4yz4sjkk8m5jqay0xzgfq9jwrw6 --out-file /dev/stdout --testnet-magic 42 --cardano-mode
{
    "96003f81df15b6d26f62a88d83b31ca9670bcfec4ea82ce739777ff20409e1fd#0": {
        "address": "addr_test1vrktl4mg8w83dl8untnmn99maz4yz4sjkk8m5jqay0xzgfq9jwrw6",
        "value": {
            "e48c26399203edda32b52d52fd7c4d3566f350a037efbff00aedf883": {
                "ěůřščžďťňdxjk": 5
            },
            "lovelace": 899808231
        }
    }
}

[rvl]

Just noting that from your examples, it appears to me that cardano-cli is working correctly w.r.t. unicode.
If the user's character encoding is ASCII, then all characters >= 0x80 are rejected as non-alphanumeric.

But if test cases use the UTF-8 encoding for unicode characters, then this shell.nix change is necessary to force a UTF-8 locale in the shell.

[rvl]

bors r+

[iohk-bors]

Build succeeded:

• buildkite/cardano-node
• ci/hydra-eval
• ci/hydra-build:required