Brainfart: switch(get_value(), v -> if(v = 1, 'First'), v -> if(v = 2, 'Second', 'Default'))

[gertjanal]

Description

Switch cases in a single expression are usually written like this:
CASE get_value() WHEN v = 1 THEN 'First' WHEN v = 2 THEN 'Second' ELSE 'Default' END

With the function of this PR, the expression can be written like this:
switch(get_value(), v -> if(v = 1, 'First'), v -> if(v = 2, 'Second', 'Default'))

It is shorter, but also allows more complex implementations like:
v -> if(is_valid_value(v), 'First')
or
v -> if(v = 2 OR v = 3, 'Second'):

switch(get_value(), v -> if(is_valid_value(v), 'First'), v -> if(v = 2 OR v = 3, 'Second', 'Default'))

I wonder if anyone sees any potential in this function. It was fun to implement it. When a case returns NULL, the next case is tested.

Release notes

I'll add this later when the PR is approved

[github-actions]

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