libj4status-plugin: Add a colour API

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
J4statusSection: Allow to override the colour

i3bar: Add support

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
J4statusSection: Allow to add a label colour

i3bar: Add support

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
J4statusSection: Allow to specify alignment

i3bar: Add support

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
sensors: Set the section value max width

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
upower: Set the section value max width

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
systemd: Set the section value max width

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>