Map layer con­trols

• Im­prove the user in­ter­face for show­ing and hid­ing map lay­ers
• Add an op­tion to show only one map layer at a time, dras­ti­cally in­creas­ing per­for­mance for large, mul­ti­layer datasets

Bug fixes and in­ter­nal im­prove­ments

• Fix pro­ject file share sheet
• Prop­erly up­grade pro­jects from older ver­sions on app startup
• More ef­fi­cient han­dling of app ini­tial­iza­tion and pro­ject load­ing
• Im­prove mes­sage pass­ing at the top lev­els of the app
• Up­date the un­der­ly­ing data­base frame­work to work with iOS 18