Change Xcode project developmentRegion to 'en' and plist CFBundleDevelopmentRegion to DEVELOPMENT_LANGUAGE (#34293)

* Updating dart.dev related links

* Update packages/flutter_tools/lib/src/base/context.dart

* Update packages
* Capture JSON RPC errors that presently get swallowed

Currently, in pubspec.yaml, semver.org is referred to for more about versioning.
However, the versionCode/versionName could differ on different platforms (iOS, Android, Dart).

This adds more clear and complete information that could help users to understand it better.

See: #27251

* Update packages

* Change test for isFile

This reverts commit 30f33d6c.

Fixes https://github.com/flutter/flutter/issues/26544

* move flutter_assets to App.framework

* Roll engine to 05fee4eeee0ff6b219b1fcc394371e5f6963cc46

05fee4eee Update default flutter_assets path for iOS embedding (flutter/engine#7518)
02205db01 Roll src/third_party/skia 5d052dac3ac1..02738a86e5fd (4 commits) (flutter/engine#7541)
af907c074 Roll src/third_party/skia 5c7a3ac0e214..5d052dac3ac1 (7 commits) (flutter/engine#7540)
dde286673 IWYU to get SkFontMetrics (flutter/engine#7539)

This reverts commit d8db70af.

* move flutter_assets to App.framework

* remove flutter_assets references from all pbxproj files checked in

Fixes https://github.com/flutter/flutter/issues/25703

Profile builds need access to sockets in order to launch the Dart
observatory server.

This permission used to be enabled by default in all build types,
but was moved to a build type specific manifest in
https://github.com/flutter/flutter/commit/88b853f7eb85bf0b47e1ca4d1bf9d9a9f821730d

* Remove *.lock from gitignore

* Remove pubspec.lock from gitignore

We hypothesize that many first-time users creating a new project will look at the README.md as a starting point for "what next". As we've updated our documentation particularly for new users, having better links to our codelabs and cookbooks will help them be productive.

* Update IntelliJ project template files

* Add ignored file

* Fix test

* Restore comma

* Use Xcode build configurations to drive Flutter build mode

* Proper check wrt local_engine, print error if profile mode misisng

* Remove unused code, update tests, fix template problem, update warning

* fix up warning

* add explanatory dev comment

* fix whitespace

* missing words, change lambda arrow to function body

* error indentation

* Test early exits for xcode_backend.sh

* only on macOS, use right test

* Update error messages

* case insensitive compare for build config

* Update gallery podfile

* update projects to add profile configuration

* make compatible with flavors

* add missing plist files

* add FLUTTER_FRAMEWORK_DIR back, set swift version for profile, tell Podfile about profile

* update the docs for the module template

* update text

* Revert "Update templates (#23698)"

This reverts commit 5b0de6d6.

* Revert "Verify that date/number translations exist for all supported languages (#23692)"

This reverts commit 3449edf2.

* Revert "Reland Xcode backend refactor (#23574)"

This reverts commit 7270f284.

Removes some `new`s and other minor cleanup.

* Use Xcode build configurations to drive Flutter build mode

* Proper check wrt local_engine, print error if profile mode misisng

* Remove unused code, update tests, fix template problem, update warning

* fix up warning

* add explanatory dev comment

* fix whitespace

* missing words, change lambda arrow to function body

* error indentation

* Test early exits for xcode_backend.sh

* only on macOS, use right test

* Update error messages

* case insensitive compare for build config

* Update gallery podfile

* update projects to add profile configuration

* make compatible with flavors

* add missing plist files

* Update template comments

Make template comments consistent with recent tools changes

* Update packages/flutter_tools/templates/app/lib/main.dart.tmpl
Co-Authored-By: mit-mit <mit-mit@users.noreply.github.com>

* Fix merge conflict

This reverts commit def1d805.

* Use Xcode build configurations to drive Flutter build mode