conditions.is_active extended for cases when neovim focus is lost

[simonmandlik]

This is a simple extension that also reacts to the focus of neovim being lost:

vim.g.focus = true
local function is_active_with_focus()
    local conditions = require("heirline.conditions")
    return vim.g.focus and conditions.is_active()
end

vim.api.nvim_create_autocmd("FocusLost", {
    desc = "Remembering lost focus",
    callback = function()
        vim.g.focus = false
    end
})
vim.api.nvim_create_autocmd("FocusGained", {
    desc = "Remembering gained focus",
    callback = function()
        vim.g.focus = true
    end
})

can be used as direct replacement of the original conditions.is_active :)