Allow LISTEN on patterns

I implemented a LISTEN command that supports matching names in the LIKE 
format.

Just like

LISTEN 'c%';
NOTIFY c1;NOTIFY c2;

Notifications are received for c1 and c2.

For grammatical reasons, LISTEN 'v_'; with LISTEN v_; It's weird.

Should it be defined in a way that makes it easier to distinguish?
And support for more matching patterns.

For example
LISTEN [LIKE] 'like_pattern';
LISTEN SIMILAR 'regex_pattern';

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Zongliang Quan