Add support for parameters in query directives

[hhmitchell]

Currently query directives defined in a ledger can only be run as written, but it would allow for more powerful queries if they could take parameters. As a trivial example:

2100-12-31 query "foo" "select date limit %d"

Then .run foo 3 would execute the query with 3 substituted as the limit. More realistically, we could have queries like:

2100-12-31 query "bar" "select ... where year = %d and account = %s ..."

and so forth.

Brief discussion: https://groups.google.com/g/beancount/c/td18CgN1y-0

[dnicolodi]

beanquery already supports query parameters when using the Python API. The parameter format used is pyformat as defined by the DB-API PEP 249 https://peps.python.org/pep-0249/#paramstyle and used by other Python database adapters, for example psycopg https://www.psycopg.org/psycopg3/docs/basic/params.html#passing-parameters-to-sql-queries Note that this format uses %s as a nameless parameter placeholder, regardless of the type of the parameter values, and other printf-style format specifiers have no meaning.

Support for parameters to queries run with .run would use the same parameter placeholder format.

Exposing parameters substitution to queries run with .run is fairly easy. The only difficult part is to provide a reasonable user interface and error reporting. Indeed I have implemented support for parameters passed to .run at the same time I implemented query parameters in the Python API, but I haven't pushed it upstream because I felt that the UI was not a nice as it could be.

I'll brush up what I have and open a PR so people can have a look.