Improve error message when mirrord-config extension is not supported.

[josephmate]

Problem

When using a file that does not end in json/yml/yaml/toml, you get the below error:

All supported extensions are hardcoded here: https://github.com/metalbear-co/mirrord/blob/main/mirrord/config/src/lib.rs#L705

mirrord exec \
  --config-file valid \
  -- ls
  x mirrord exec
    ✓ running on latest (3.144.0)!
Error:   × Failed to verify mirrord config: mirrord-config: Unsupported configuration file format!
  ╰─▶ mirrord-config: Unsupported configuration file format!
  help: Inspect your config file and arguments provided.

Solution

Error message should say

mirrord-config: you provided file with extension {extension} but mirrord supports only json, toml, yaml, and yaml

[linear]

MBE-1025 Improve error message when mirrord-config extension is not supported.