v0.3.1-build1

Test build for v0.3.1:

• Added custom oauth for imap, cardav, and caldav (designed for and tested with Stalwart)
• Custom oauth refresh token handling fix
• Use TOFU cert store for DAV certs
• Timezone config fix
• Multi-day week and day view fix
• Multi-day monthly view fix - #304
• Composer body config - #216
• Attachment parsing improvements - #307