Improve member formatting for C++

[jchristgit]

Currently, when looking up a symbol with member using .cppref, the member formatting looks somewhat unorganized. I feel like two things could improve this by a fair margin:

• Not displaying all member types, but truncating too long types with ....
• Wrapping the member names into code blocks, e.g.:

Member Functions
(constructor)
(destructor): destroys the string, deallocating internal storage if used (public member function)
operator=: assigns values to the string
assign: assign characters to a string
get_allocator: returns the associated allocator
Element access: No description available note: this looks like redundant information
at: accesses the specified character with bounds checking
operator[]: accesses the specified character

• Sorting the member types by their names.