feat: vue2 support

[GerryWilko]

Description

This PR aims to provide support for Vue 2. The current eslint rules are based off the Vue 3 eslint rules, this PR introduces a new configuration option vue2 that when passed to the vue config will instead base the rules off the Vue 2 eslint rules.

Some of the eslint rules in the Vue 3 rulesets will introduce changes which are incompatible with Vue 2 projects. For example named v-models rather that prop.sync.

Linked Issues

Additional context

[Dimava]

🤔
Vue 2 is reaching EOL in three weeks, so I'm not sure about how useful could this be
If there is auditory for this it may be useful, but I somewhat doubt many will move from antfu-eslint@0.x or other preset without planning to drop in Vue3

[GerryWilko]

I understand this may be a bit late to the party however I do feel Vue 2 support even if just on the basis of the base rules being swapped will be helpful to a large number of people.

Some members of the core Vue team are also offering extended support (paid) for Vue 2 beyond EOL.

My team are in the process of migrating a large Vue 2 app to Vue 3 but I would like to apply these eslint rules in the meantime.

I did also pop a question over to @antfu on discord before starting and he seemed open to a PR adding support.