Automatic "PIVOT" function

Suppose you have data like this:

+-----------+-----------+-------+
| Day | Product | Sales |
+-----------+-----------+-------+
| Monday | Product A | 5 |
| Monday | Product B | 4 |
| Tuesday | Product A | 2 |
| Tuesday | Product B | 8 |
+-----------+-----------+-------+

But you want it like this:

+-----------+-----------+-----------+
| Day | Product A | Product B |
+-----------+-----------+-----------+
| Monday | 5 | 4 |
| Tuesday | 2 | 8 |
+-----------+-----------+-----------+

Then you need to "pivot", which means rearranging data from multiple rows into multiple columns.

PostgreSQL has a function `crosstab` in the `tablefunc` extension, but it is really cumbersome to use.
You can also use `CASE` or `FILTER` to create pivot tables like this, however that is also inconvenient. Also, all these methods require knowing the resulting columns beforehand.

It would be nice if we could add a feature to Postico that makes pivots easier.

Start by reviewing the requested pivot behavior alongside PostgreSQL's tablefunc crosstab extension and the CASE or FILTER alternatives described in the issue. Define how Postico should create pivoted columns without requiring the resulting columns beforehand; done means the sample Day/Product/Sales data can be rearranged into the shown pivoted table.

Written by the indexing model from the issue text.