Consider optimizing chevrotain DSL parsing logic on input change

[dkumiszhan]

Currently we parse the event filter using chevrotain DSL definition when user types. When user clicks Apply, we parse the same filter again. We can do some optimization by persisting the result of filter parsing on input change and reusing it on pressing Apply button. Things to consider here is that persisted event might be out of date or invalid.

[glaslos]

Obsolete due to a misunderstanding on my side.