I want to allow players to spawn non-shopkeepers villagers through spawner egg is it possible or it isnt ?

It is, in the following ways:

• If the player is in creative-mode, the spawner egg will work like normal.
• If the player is holding the spawner egg in his off-hand, it will work like normal.

You will also have to set prevent-shop-creation-item-regular-usage to false (which it is by default).

Alternatively, you could also change the shop creation item to something else.