Improved code snippets and autocompletion

[pawelsalawa]

Default code snippets should be initialized with common queries, such as:

SELECT * FROM :table_name;

SELECT * FROM :table_name WHERE :conditions;

DELETE FROM :table_name WHERE :conditions;

INSERT INTO :table_name (:columns) VALUES (:values);

UPDATE :table_name SET :assignments WHERE :conditions;

Then the code assistant should consider completion for empty SQL to be completion for templates (should switch to templates view initially - this should be configurable). This will allow users to quickly start typing queries from empty input.

Finally, any placeholders (:token) should be preselected one by one to be replaced by user. Tab-key should move to next :token, until last one is tabbed-out. This (token replacing) should work generally for all code snippets.

Tokens should be detected by tokenizer, as user may use :value inside of string, or quoted object name.