Add packet color and text style highlighting

[NghiaTranUIT]

• Add 11 highlight colors to the packet menu.
• Add Command+1 to Command+9 shortcuts.
• Add strikethrough with Command+/.
• Add reset with Command+0.
• Add a separator above Highlight.
• Apply styles to one or many selected packets.
• Keep colors visible on selected rows.
• Use readable colors in light and dark mode.
• Save styles in pcap and pcapng exports.
• Save styles in TCP Viewer session files.
• Keep capture files readable in other apps.
• Keep old TCP Viewer sessions working.
• Add tests for styles, exports, and compatibility.

[NghiaTranUIT]

Done 👍