Fix column widths for doctor command's dependencies table

[ianmjones]

When a package name is exactly 16 characters long (or any higher multiple of 8 as used for tab width), its name hits the following Status column, as seen with nixos.pkg-config below:

ian@ians-apollo:~ $ wails doctor
Wails CLI v2.0.0-beta.43

Scanning system - Please wait (this may take a long time)...Done.

System
------
OS:             NixOS
Version:        22.11
ID:             nixos
Go Version:     go1.18.4
Platform:       linux
Architecture:   amd64

Wails
------
Version:                v2.0.0-beta.43
Package Manager:        nixpkgs

Dependency      Package Name    Status          Version
----------      ------------    ------          -------
*docker         nixos.docker    Installed       20.10.17
gcc             nixos.gcc       Installed       11.3.0
libgtk-3        nixos.gtk3      Installed       3.24.34
libwebkit       nixos.webkitgtk Installed       2.36.5
npm             nixos.nodejs    Installed       16.16.0
*nsis           nixos.nsis      Available       3.06.1
pkg-config      nixos.pkg-configInstalled       0.29.2
*upx            nixos.upx       Installed       3.96

* - Optional Dependency

Diagnosis
---------
Your system is ready for Wails development!
Optional package(s) installation details:
  - nsis: nix-env -iA nixos.nsis



If Wails is useful to you or your company, please consider sponsoring the project:
https://github.com/sponsors/leaanthony

This PR gives each entry at least a single space before the next column:

ian@ians-apollo:~/Projects/github.com/ianmjones/wails/v2/cmd/wails (master) $ wails doctor
Wails CLI v2.0.0-beta.43

Scanning system - Please wait (this may take a long time)...Done.

System
------
OS:             NixOS
Version:        22.11
ID:             nixos
Go Version:     go1.18.4
Platform:       linux
Architecture:   amd64

Wails
------
Version:                v2.0.0-beta.43
Revision:               ba11e5c6d6d6ac6c01ec29d7172adb3115fc47cb
Modified:               true
Package Manager:        nixpkgs

Dependency      Package Name            Status          Version
----------      ------------            ------          -------
*docker         nixos.docker            Installed       20.10.17
gcc             nixos.gcc               Installed       11.3.0
libgtk-3        nixos.gtk3              Installed       3.24.34
libwebkit       nixos.webkitgtk         Installed       2.36.5
npm             nixos.nodejs            Installed       16.16.0
*nsis           nixos.nsis              Available       3.06.1
pkg-config      nixos.pkg-config        Installed       0.29.2
*upx            nixos.upx               Installed       3.96

* - Optional Dependency

Diagnosis
---------
Your system is ready for Wails development!
Optional package(s) installation details:
  - nsis: nix-env -iA nixos.nsis



If Wails is useful to you or your company, please consider sponsoring the project:
https://github.com/sponsors/leaanthony

[leaanthony]

Nice one @ianmjones ! Thanks for doing this! 🚀