Refactor into smaller composable components

[dylan-smith]

Split it up into many smaller components:

• add-dive-segment
• ceiling-chart
• current-stats
• custom-gas-input
• depth-chart
• dive-overview
• dive-plan
• dive-settings
• dive-summary
• end-chart
• error-list
• graph-dialog
• new-depth-stats
• new-dive
• new-gas-input
• new-gas-stats
• new-time-stats
• po2-chart
• standard-gas-list
• start-gas-stats
• tissues-ceiling-chart
• tissues-phe-chart
• tissues-pn2-chart