feat: Implement colored output (with `NO_COLOR` support)

Colours sould only be enabled when the terminal supports them.
For example, when redirecting output or piping to cat, there should be no escape sequences.

I believe there needs to be a condition around the pretty method (or maybe it should be handled by tracing_subscriber::fmt):

https://github.com/stackabletech/stackable-cockpit/blob/fe37d494359d91e32ae309a9f6d382b4a486c5a0/rust/stackablectl/src/main.rs#L31

Examples:

stackablectl --log-level=DEBUG stack list > /tmp/stackablectl.stdout       # plain redirect
stackablectl --log-level=DEBUG stack list | cat > /tmp/stackablectl.stdout # pipe through cat
TERM= stackablectl --log-level=DEBUG stack list > /tmp/stackablectl.stdout # explicitly set TERM to nothing

If I open it in VIM, it looks like this:

从 rust/stackablectl/src/main.rs 中链接的 pretty 方法附近开始，比较 tracing_subscriber::fmt 是否应负责终端检测。使用重定向和管道输出运行列出的 stackablectl 命令，包括 TERM 为空的情况，并确认非交互式输出不包含转义序列，而受支持终端的输出仍保持彩色，并且遵循 NO_COLOR。