Fix UTF-8 console input/output on Windows

[HertzDevil]

Fixes #11527. Uses the chcp 65001 approach.

[HertzDevil]

Minor note: the following will not work on Visual Studio Code by default:

> chcp 65001
Active code page: 65001

> crystal eval puts ×😂 | code -

The result would still be ×😂, which is the UTF-8 byte sequence reinterpreted in codepage 437. This is because VSCode picks up the system code page, not the one in the terminal session. This is not Crystal's fault and is unaffected by this PR. The following also produces garbled text:

> echo 😂 | code -

The workaround is to change the system code page as noted above, or set the VSCODE_CLI_ENCODING=UTF-8 environment variable.