Feat: add option to show tmux's status line on lualine

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Requested feature

recently i moved tabs from the tabline on the top to the lualine on the bottom, and it feels great! it would be really nice to be able to see tmux tabs on the lualine. this way i would have only one status line at the bottom of the editor with everything from tabs to tmux on it.

Motivation

currently it takes up 3 lines on the bottom, one for the tmux status line, one for the cmd area and one for lualine. that would be reduced to two, and believe me it would be a big improvement, tabs on the left of lualine and tmux tags on the right.