Trim trailing spaces from retrieved strings in EF Core

ASP.NET MVC Core 5 application uses Npgsql Entity Framework Core Data Provider to get data from Postgres database using Entity Framework Core. Columns in database are defined as CHAR(n) type, like

    create table prpalk (
    sfirmanimi char(100);
    )

Column types cannot changed to varchar.

Using EF commands like string nimi = ctx.Prpalks.Single().Sfirmanimi; to get data, strings in application contain also trailing spaces. How to remove trailing spaces automatically ?

Is there some event in EF Core which can used to trim all string columns when returned to application ?

I havent found such setting in EF data provider, Npgsql or Postgres database.

Column types cannot changed to varchar type due to compatibility with existing legacy application.