Add declaration keyword and swap type and variable names

I see the article. https://github.com/dart-lang/language/blob/master/resources/optional-semicolons-prototype.md

Add declaration keyword and swap type and variable names, Is have plan break change dart syntax on dart 3?

example;
1. declaring variables

from
```dart
var a = 1
int a = 1
```

change to
```dart
var a = 1
var a:int = 1
```

2. declare functions

from
```dart
int dosomething(){}
```
change to
```dart
function dosomething() int{}
```

I know this change is difficult, but for me, who is used to the typescript and swift syntax, I feel more comfortable writing code this way

this syntax change is undoubtedly helpful in solving the optional semicolon problem

Start by reading resources/optional-semicolons-prototype.md and compare its goals with the proposed declaration and function syntax in the issue. This is a language-design proposal rather than a localized code change; done would require a settled compatibility decision and an accepted specification or design update, none of which the issue currently identifies.

Written by the indexing model from the issue text.