feat(builtin): allow picking help pages and colorschemes not yet loaded by Lazy.nvim

[mehalter]

Description

This extends the built in help_tags and colorscheme pickers to support selecting from plugins that are not yet loaded by the Lazy plugin manger as described by the developer (ibhagwan/fzf-lua#1296). I have fully tested this and it works great even if the user doesn't use lazy.nvim and is a non-breaking change.

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

• Have a plugin that is lazy loaded (lazy = true) and not yet loaded into the editor that provides a colorscheme. Run :Telescope colorscheme and see that it is on the list. When selecting it, it successfully loads automatically and is displayed
• Have a plugin that is lazy loaded (lazy = true) and not yet loaded into the editor that provides a help docs. Run :Telescope help_tags and search for the plugin, select one and see that you can view the help page

Configuration:

• Neovim version (nvim --version): Nvim 0.10.1
• Operating system and version: Arch Linux, latest

Checklist:

• My code follows the style guidelines of this project (stylua)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (lua annotations)

[Conni2461]

thanks :)