feat: add new v-bind-same-name-style rule

[waynzh]

close #2359.

Still figuring out how to categorize and set default value for this new rule. For now, I've set never as the default to avoid causing any breaking changes.

[ota-meshi]

Thank you for working on this change.
However, I would rather add new options to existing vue/v-bind-style rule than add new rule. What do you think?
(Sorry, I should have commented on this earlier.)

[waynzh]

I would rather add new options to existing vue/v-bind-style rule

Thanks for your input.

I've been contemplating whether to integrate this feature within the existing rule or to implement it as a separate one. I'm later leaning towards a separate rule as this rule particularly targets for cases where the key and value are the same name, one could use in longform and still omit the value.

Before next move, I'd like to gather opinions on the best way to incorporate this feature in vue/v-bind-style. Here are some options I'm considering:

1. Introduce a sameNameShorthand enum that keeps the rule in shorthand form (e.g., :foo=”bar”) and omits the value only when it has same name :foo="foo" → :foo .
2. Modify the option to accept an array, allowing for combinations like ['longform', 'sameNameShorthand']. So they can be v-bind:foo="bar", but v-bind:foo="foo" → v-bind:foo. (But ['longform', 'shorthand'] is invalid one.)
3. I'm open to other suggestions as well.

What do you think? I'm looking forward to your insights.

[ota-meshi]

My idea is to add a third object option.
This is probably what @FloEdelmann wrote in #2359.

{
   "vue/v-bind-style": [
     "error",
     "shorthand", // "shorthand", or "longform"
     {
       "sameNameShorthand": "ignore" // "always", "never", or "ignore"
     }
   ]
}

[waynzh]

Yeah, that makes sense to me. I'll close this PR for now, and when I find some time, I'll complete it and then open a new one.