feat: adds info command to show env vars and config files

[YummyOreo]

Fixes #1542
Adds atuin info that prints config locations and version information (see below). This could be a sub command, but IDK what command it would fall under. Possible a new command like atuin config that would reset the config (just an idea)?

Config files:
client config: ~/.config/atuin/config.toml"
server config: "~/.config/atuin/server.toml"
client db path: "~/share/atuin/history.db"
key path: "~/.local/share/atuin/key"
session path: "~/.local/share/atuin/session"

Env Vars:
ATUIN_CONFIG_DIR = "None"

Version info:
version: 18.0.2

Checks

• I am happy for maintainers to push small adjustments to this PR, to speed up the review cycle
• I have checked that there are no existing pull requests for the same thing

[ellie]

this is nice, thank you!

[llimllib]

Thanks @YummyOreo !