SEC-2325: Polish CSRF Tag support

- Rename csrfField to csrfInput
- Make AbstractCsrfTag package scope
- rename FormFieldTag to CsrfInputTag
- rename MetaTagsTag to CsrfMetaTagsTag
- removed whitespace from tag output so output is
  minimized & improving browser performance
- Update @since
- changed test names to be more meaningful

docs/manual/src/asciidoc/index.adoc

@@ -3139,7 +3139,7 @@ The last step is to ensure that you include the CSRF token in all PATCH, POST, P
 </form>
 ----
 
-An easier approach is to use <<the-csrffield-tag,the csrfField tag>> from the Spring Security JSP tag library.
+An easier approach is to use <<the-csrfInput-tag,the csrfInput tag>> from the Spring Security JSP tag library.
 
 [NOTE]
 ====
@@ -5037,17 +5037,17 @@ The permissions are passed to the `PermissionFactory` defined in the application
 This tag also supports the `var` attribute, in the same way as the `authorize` tag.
 
 
-=== The csrfField Tag
+=== The csrfInput Tag
 If CSRF protection is enabled, this tag inserts a hidden form field with the correct name and value for the CSRF protection token. If CSRF protection is not enabled, this tag outputs nothing.
 
-Normally Spring Security automatically inserts a CSRF form field for any `<form:form>` tags you use, but if for some reason you cannot use `<form:form>`, `csrfField` is a handy replacement.
+Normally Spring Security automatically inserts a CSRF form field for any `<form:form>` tags you use, but if for some reason you cannot use `<form:form>`, `csrfInput` is a handy replacement.
 
 You should place this tag within an HTML `<form></form>` block, where you would normally place other input fields. Do NOT place this tag within a Spring `<form:form></form:form>` block—Spring Security handles Spring forms automatically.
 
 [source,xml]
 ----
     <form method="post" action="/do/something">
-        <sec:csrfField />
+        <sec:csrfInput />
         Name:<br />
         <input type="text" name="name" />
         ...