- Support simple queries that do not select
data from tables. This is similar to `values ..`,
but allows to add aliases for expressions.
- Such selects can also be used in subqueries
- Examples:
```
select 1;
select (select count(*) from t);
select 2 as foo, 3 as bar;

select a from t
where b in (select 100)
```

- Support like operator with signature:

expr1 LIKE expr2 [ESCAPE expr3]

which returns TRUE only if expr1 matches the
string specified by expr2 (pattern). '_' in
pattern matches any single character, '%'
matches any character 0 or more times. All
other characters match itself according to
case.

- Optional escape clause specifies character
to use for escaping '_' and '%'

feat: support ALTER SYSTEM. It allows to change whitelisted properties from _pico_property table. Currently, changes affect all tiers. Specifying tier will result in an error.

Co-Authored-by: Dmitry Rodionov <d.rodionov@picodata.io>

Co-Authored-by: Emir Vildanov <e.vildanov@picodata.io>

Affected diagrams:
— expression
— literal
— call
— type

Extracted diagrams:
— case
— to_char
— to_date
— trim

Definition:
https://git.picodata.io/picodata/picodata/sbroad/-/blob/b1b021bff1ea23aa8d0fb74a0ed0fd409043a6bb/sbroad-core/src/frontend/sql/query.pest#L205-208

Definition:
https://git.picodata.io/picodata/picodata/sbroad/-/blob/b1b021bff1ea23aa8d0fb74a0ed0fd409043a6bb/sbroad-core/src/frontend/sql/query.pest#L173-179

Definition:
https://git.picodata.io/picodata/picodata/sbroad/-/blob/b1b021bff1ea23aa8d0fb74a0ed0fd409043a6bb/sbroad-core/src/frontend/sql/query.pest#L186

- to_char(datetime, format), format is specified
as in `strftime` function:
https://man.freebsd.org/cgi/man.cgi?query=strftime&sektion=3