Improve macOS app integration (#746)

* Improve macOS app integration

Tart is now a proper application bundle, with the name and icon
declared in the Info.plist, which we were missing.

This also allows us to declare the app as LSBackgroundOnly
as a default, which means that 'tart create' and similar
background commands will not show the application icon in
the dock, while 'tart run' will, thanks to it overriding
the activation policy of the app.

For now the logic of creating the Tart.app bundle is duplicated
between the CI packaging scripts and the run-signed.sh script.
Now that these scripts are growing, it makes sense to look
at whether we can share the logic somehow, e.g. by building
the application bundle directly during build, and packaging
that, instead of creating it as a post install step.

* Integration tests: fix DockerContainer import

To work around the breaking change in 4.0.0,
see https://github.com/testcontainers/testcontainers-python/commit/383b12e9d63b4b105c65e587e87c380355871a36.

* .cirrus.yml(Release (Dry Run)): no need to install Sentry CLI

---------

Co-authored-by: Nikolay Edigaryev <edigaryev@gmail.com>

Resources/Info.plist

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+    <key>CFBundleName</key>
+    <string>Tart</string>
+    <key>CFBundleIdentifier</key>
+    <string>org.cirruslabs.tart</string>
+    <key>CFBundleExecutable</key>
+    <string>tart</string>
+    <key>LSBackgroundOnly</key>
+    <string>1</string>
+    <key>CFBundleIconFiles</key>
+    <array>
+        <string>AppIcon.png</string>
+    </array>
+</dict>
+</plist>