Make provider holdable

[root-expert]

Pull Request (PR) description

Makes provider holdable via mark property. If a package is held it prevents refreshes for the specified time defined by the hold_time install option.

hold_time can be:

• forever
• time format defined by RFC3339

It's not necessary to define the time in full, e.g 2024-10-10 will work, as well as 2024-10-10T23:59

Example snippet

package { 'hello-world:
   ensure   => 'latest/stable',
   mark     => 'hold',
   provider => 'snap',
}

This Pull Request (PR) fixes the following issues