Add color config options for the list command

Add color config options for the list command so that the user can
customize the colors used in the output of the list command. This
includes the following config options within the list command section.

alternate_patch_series_colors
patch_background.color
patch_background.alternate_color
patch_index.color
patch_index.alternate_color
patch_sha.color
patch_sha.alternate_color
patch_summary.color
patch_summary.alternate_color
patch_foreground.color
patch_foreground.alternate_color
patch_extra_info.color
patch_extra_info.alternate_color

All `color` and `alternate_color` config options by be set either with
RGB values as follows.

patch_index.color.RGB = [255, 232, 18]
patch_index.alternate_color.RGB = [15, 30, 50]

Or with color names.

patch_index.color = "White"
patch_index.alternate_color = "Blue"

The alternate_patch_series_colors option is simply a boolean.

[changelog]
added: alternating of all colors for every other patch series
added: alternate_patch_series_colors config option to list command
added: patch_background.color config option to list command
added: patch_background.alternate_color config option to list command
added: patch_index.color config option to list command
added: patch_index.alternate_color config option to list command
added: patch_sha.color config option to list command
added: patch_sha.alternate_color config option to list command
added: patch_summary.color config option to list command
added: patch_summary.alternate_color config option to list command
added: patch_foreground.color config option to list command
added: patch_foreground.alternate_color config option to list command
added: patch_extra_info.color config option to list command
added: patch_extra_info.alternate_color config option to list command
changed: default colors for list command to 24-bit color mode

<!-- ps-id: 03619610-5ec3-4e73-ae12-59d1b369bd65 -->

Co-authored-by: Drew De Ponte <cyphactor@gmail.com>
Signed-off-by: Ali Caglayan <alizter@gmail.com>
Signed-off-by: Drew De Ponte <cyphactor@gmail.com>