Bug #85791 for Sub-Infix: Add more overloading for other operators

Sub::Infix could overload other operators, in my testing the following work (and are not unpleasant characters for :

• %infix%
• +infix+
• *infix*
• **infix**

Unfortunately -infix-, while it works, does so with warnings (Ambiguous use of -plus resolved as -&plus() at test.t line 7.) due to the stringification behaviour of unary '-'.  Might be worth adding it with a caveat that () is required, since an -infix()- operator syntax seems worth the extra ()s.

Also currently possible with Sub::Infix  but might be worth explicitly documenting:

• Adding global operators with control characters, punctuation and numbers but which require the & before them when used (<<&1>>, /&*/)
• Putting named operators into namespaces: <<String::concat>>, <<Array::push>>, |Method::1|