add quick level filter, which allows filtering logs by level according to Log Level Rules and the base level field

[arturminchukov]

First part of issue #108

Describe Your Changes

Added quick level filter, which allows filtering logs by level according to Log Level Rules and the base level field.
You can select several levels using shift.
How it works:

1. if no query, then use the level query
2. if the query exists, then looking for pipe function ----> filterName1: filterValue1 | filterName2: filterValue2
3. if no pipe, go to step (5) ----> filterName1: filterValue2
4. if a pipe exists, find the first part of the query ----> filterName1: filterValue1
5. looking for other level filters in the query ----> filterName1: filterValue1 level: info
6. If the level filter exists, add a new level filter at the beginning of the query ----> level: newinfo filterName1: filterValue1 level: info ...
7. if the level filter doesn't exist, add a new pipe, and before pipe add level filter ----> level: newinfo | filterName1 ...

The "Unknown" filter has a different behavior:

1. Selecting the unknown filter will deselect other filters.
2. Selecting the 'other' filter when the unknown filter is selected will deselect the unknown filter.

Demo video:

Screen.Recording.2025-12-10.at.17.51.51.mov

Checklist

The following checks are mandatory:

• My change adheres to VictoriaMetrics contributing guidelines.
• My change adheres to VictoriaMetrics development goals.

[dmitryk-dk]

LGTM!