Support Charset for character encoding in MockMvc #27231
Description
#27230 introduced support for configuring the default character encoding in the underlying MockHttpServletResponse used in MockMvc, using a Charset.
However, methods for supplying character encoding in MockHttpServletRequestBuilder and ContentResultMatchers currently accept a String.
To improve the developer experience and avoid the use of String literals, we should provide overloaded support via Charset for character encoding in MockHttpServletRequestBuilder and ContentResultMatchers.