Allow expressions in filter columns

[rbayet]

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PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[X] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Other... Please describe:

What is the current behavior?

Issue Number: N/A
The current behavior: the table filters are constructed which before this PR only allow a scalar, i.e. actual column value (as first argument).
This does not allow to build a condition where the subject/column is actually an expression.

What is the new behavior?

As for the filter value, allows using the syntax 'expr: [My SQL expression]' as a filter column, for instance

my_table:
    filters:
       - ["expr: COALESCE(foo, '')", 'notLike', '%bar%']

if you wish to exclude the rows of my_table where the foo column contains 'bar' but also keep the rows where foo is null.

Does this PR introduce a breaking change?

[ ] Yes
[X] No

Other information

Due to the way the filters interpretation is done, I was not able to add a specific unit test.