[feat] Allow mask of model be in certain block

[nekosu]

Clear and concise description of the problem

Currently, the mask of model always fill the whole screen, while sometimes I only need to prevent user from accessing certain area.

Suggested solution

Allow model only mask the block that it lives in.

Alternative

Add new component to provide a customizable mask.

Additional context

Consider the behavior of vuetify v-overlay

Validations

• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.