Add new option to hide voting when not allowed

[hackerESQ]

Fixes #32 and somewhat related to v17development/flarum-support-feedback#14

Changes proposed in this pull request:
This adds a new option in extension settings that allows admins to hide voting options when the post/tag/user does not have permissions to vote.

Reviewers should focus on:
This only adds a new configuration option. But perhaps the logic to hide should be reviewed:

if (setting('hideIfNoPermissions', true) && !post.canVote() && !post.canSeeVotes()) {
   return;
}

This same logic was added to the alternate layout as well.

Screenshot

Confirmed

• Frontend changes: tested on a local Flarum installation.
• Backend changes: tests are green (run composer test).

Required changes:
N/A