Configurable timeout to send text change events from server

Steps to reproduce

1. Generate a lot of pages https://wiki.magnolia-cms.com/display/Support/Groovy+scripts#Groovyscripts-Createalotofpages (Can by run multiple times)
2. Go to pages app https://nightly.magnolia-cms.com/.magnolia/admincentral#app:pages-app:detail;/travel:edit
3. Type letter by letter into the filter of the "Title" column

Actual result:

The UI/typing is slow, server is under stress.

Expected result:

As developer I can configure the filtering to be less extensive in huge repos.

Alternative solution:

Currently, the grid filtering kicks in every time users type a character into a text filter. However, this has a performance implication, and some customers prefer to wait till they have at least three characters in the search query.

We can make this configurable to help the customers.

• Default minimum characters set to 3 
• Configurable option to change the minimum characters required