add defaultVariables options to initialize properties

[binyar]

In my project, there will be a lot of the same local app data variabls:
e.g

{
"a": "Hello,{appName}",
"b": "Hi,{appName}",
"c": "Good well,{appName}",
...
}

JS code (Before)

// file1
Intl.get('a',{appName:'wahaha'});
// file2
Intl.get('b',{appName:'wahaha'});
// file3
Intl.get('c',{appName:'wahaha'});

JS code(After)

intl.init({
 ...
defaultVariables:{
 appName:"wahaha"
}
})
// file1
Intl.get('a');
// file2
Intl.get('b');
// file3
Intl.get('c');

I want to use a default variables to avoid generating a lot of duplicate code

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[cwtuan]

please add some test cases.

[binyar]

please add some test cases.

hi bro, maybe you can have a look at of this,I will use the feature plz.

[cwtuan]

Please don't include personal or compony information in the test cases.