Fix: number based alerts evaluation isn't working

[arikfr]

What type of PR is this? (check all applicable)

• Bug Fix

Description

Following the alerts new UI, all the threshold values are saved as strings. This change casts the value into a number, if the query result value is a number.

Related Tickets & Documents

Closes #4279.

[arikfr]

I updated the logic:

• Because boolean values are detected a numbers, I revised the test to make sure to exclude strings.
• Cast all non number values to strings to make it possible to compare with a string.
• In case of booleans, we cast to string and lower case (True -> true) because upper cased boolean values is Python specific and will be confusing for most users.

[ranbena]

• In case of booleans, we cast to string and lower case (True -> true) because upper cased boolean values is Python specific and will be confusing for most users.

To back it up, I believe a bool value will appear lowercase in the alert column value preview.