Allow selection of multiple filters (for bulk actions) in Filter editor

# Issue Details

#### Hello! :wave:
 
Basically, in the `(DNS) Filter Editor`, I would like to be able to select multiple filters at once, for bulk actions. Just like with rules.

**Why?** Especially for list maintainers and frequent private/public rule makers, it would be very useful when doing various tests (to let only `User rules` enabled quickly, etc.).

#### Thanks in advance! :thumbsup:
 
# Proposed solution

### :a: Basic implementation
Allow to use CTRL and SHIFT keys _(combined with mouse — or up/down arrow keys for the latter)_ to define the selection. And Space bar to toggle the enabled/disabled state on the set.

##### :bulb: Advantages
- Not too complicated to implement I would say and
- consistent with the fact that already feasible on the rules.
 
### :b: More advanced implementation _(complementary to the first one)_
A global checkbox above/below the filters for _selection_.
Once ticked, a selection checkbox appears on each filter, possibly on the left.

:thought_balloon: View implementation idea …
 

In case the left position is chosen, I would say … migrate permanently the _state_ ones to the right, in the form of toggle switches, as used in the `AdGuard Browser extension`, and make them gray/untouchable during a selection, only left for information about the current status to the user during his selection.

 
### :a: or :b: Common things …

Reveal …

###### :eye_speech_bubble: In both cases, with an slight adaptation to pluralize in the bottom gear icon menu `Enable filter` and `Disable filter` when multiple filters are selected.

###### :eyes: In both cases, once multiple filters are selected, ideally show the AdGuard mascot on the right panel — and _possibly_ duplicate there the bottom available actions on them in the form of green buttons: _Enable_ (or Enable selection), _Disable_ (or Disable selection) and maybe also _Delete_ (or Delete selection). _Think about mail clients._

 
# Alternative solution

**Basic implementation** _only_ added for now for this **v7**.

**More advanced implementation** added later in the **v8** — to take advantage of both the renewal of the user interface and the new features¹ scheduled for addition at this place to add a global checkbox at the top or bottom of the list of filters.

###### ¹ See [this issue](https://github.com/AdguardTeam/AdguardForWindows/issues/4161) and [that one](https://github.com/AdguardTeam/AdguardForWindows/issues/4166) — which is handled in the first one.