feat(content): improve reactivity

[AlexanderBelokon]

Added reactivity support to bindings, event handling and v-model support for vue components

Types of changes

• Bug fix (a non-breaking change which fixes an issue)
• New feature (a non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Description

Allows content creators to use @ and v-on, makes : and v-bind: reactive and allows to use v-model with custom components that use value field and emit input events with raw values (or emit change events and use v-model with .lazy modifier)
Resolves #519

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes (if not applicable, please state why)

[benjamincanac]

@AlexanderBelokon Thanks a lot for this PR. Sorry for the delay, would you mind fixing the conflicts before we can review?

[AlexanderBelokon]

Sure, the conflict arose because the first commit of this PR was already merged as #685

[AlexanderBelokon]

Done! Thank you for your time and for such an awesome project!)

[atinux]

Awesome work @AlexanderBelokon 💚