[5.6] Add whereJsonContains() to SQL Server

[staudenmeir]

Adds Builder::whereJsonContains() (#24330) to SQL Server 2016+ using OPENJSON().

While MySQL and PostgreSQL expect the binding as a JSON string, SQL Server requires the raw value.
This is why we need a separate prepareBindingForJsonContains() method.

compileJsonContains() has to differentiate between columns without and with a path (column->path).
In the first case, we have to wrap the column in OPENJSON(). In the second case, we have to replace JSON_VALUE() (coming from wrapJsonSelector()) with OPENJSON(). I also added tests for path-less columns to MySQL and Postgres.

There are three limitations:

• NULL values don't work.
• Boolean values only work as strings. The downside is that this also finds "true"/"false" strings.
• Arrays don't work: ->whereJsonContains('options->languages', ['de', 'en'])
  In MySQL and PostgreSQL this can be used as the short version of ->whereJsonContains('options->languages', 'de')->whereJsonContains('options->languages', 'en').