Allow to sort all json objects by key (in settings, set by default)

[rualark]

Example:
{
"B": 1,
"A": 2,
"C": 3
}

Should be:
{
"A": 2,
"B": 1,
"C": 3
}

Why:
in large jsons it is difficult to find fields

[lahmatiy]

Currently it's possible to sort kets per object in struct view (see "keys with arrow" button when keys are unsorted). It can be configurable. However it should not to be turned on by default since order of keys usually makes sense (e.g. "id" field goes first, or "start" and "finish" props should be together in that order and so on).