Use current window separators for the current window format

[SfinxNT]

To enable the use of @catppuccin_window_status_style "custom", we need to use the existing parameter @catppuccin_window_current_right_separator. This is necessary to ensure the correct separator is used in window-status-current-format.

Additionally, a popup-style change is required to maintain consistency with transparent background setups.

[SfinxNT]

Same config used

set -g @catppuccin_flavor 'frappe'
set -g @catppuccin_status_background "none"
set -g @catppuccin_window_status_style "custom"
set -g @catppuccin_window_number_position "right"
set -g @catppuccin_window_current_number_color "#{@thm_peach}"
set -g @catppuccin_window_current_text_color "#{E:@catppuccin_window_text_color}"

set -g @catppuccin_window_right_separator " #[default]#[fg=#{@catppuccin_window_number_color}]\uE0BC#[none]"
set -g @catppuccin_window_current_right_separator " #[default]#[fg=#{@catppuccin_window_current_number_color}]\uE0BC#[none]"
set -g @catppuccin_window_left_separator "#[default]#[fg=#{@catppuccin_window_text_color}]\uE0BA\u2588#[none]"
set -g @catppuccin_window_middle_separator " #[fg=#{@catppuccin_window_number_color},bg=#{@catppuccin_window_text_color}]\uE0BA#[none]"
set -g @catppuccin_window_current_middle_separator \
      " #[fg=#{@catppuccin_window_current_number_color},bg=#{@catppuccin_window_current_text_color}]\uE0BA#[none]"

set -g @catppuccin_window_text "#W"
set -g @catppuccin_window_current_text "#W#{?window_zoomed_flag, \uF05B,}"
set -g status-right-length 100
set -g status-left-length 100
set -g status-left ""
set -g status-right "#{E:@catppuccin_status_application}"
set -ag status-right "#{E:@catppuccin_status_session}"
set -ag status-right "#{E:@catppuccin_status_date_time}"

Before fix:

After fix:

[kjnsn]

Thanks so much! I've removed the popup changes from this PR, but they are welcome in another PR. I like to keep PRs focused to one change at a time.