Separate "Reset leases" button for DHCP leases (non-static)

### Prerequisites

- [X] I have checked the [Wiki](https://github.com/AdguardTeam/AdGuardHome/wiki) and [Discussions](https://github.com/AdguardTeam/AdGuardHome/discussions) and found no answer

- [X] I have searched other issues and found no duplicates

- [X] I want to request a feature or enhancement and not ask a question

### The problem

Currently, under DHCP Settings, if you click the "Reset all leases" button, it will clear out the dynamic `DHCP Leases` as well as `DHCP Static Leases`.

### Proposed solution

Add a separate button for `DHCP Leases` to clear out just the dynamic leases, preserving static leases.

### Alternatives considered and additional information

Clear all leases and manually type/paste back in the static leases, which can be quite a chore if you have more than a dozen or two static leases.