Support custom role claim

[akrambek]

Fixes #1476

[jfallows]

Let's go with roles instead of guarded.

[jfallows]

Schema should prevent empty string value if not permitted here and this code can then be simplified to remove the check.
The value of roles should be defaulted in the builder during parse to avoid implementing the defaulting logic here where options are being used.

[jfallows]

Suggested change

	List<String> roles = null;
	String path = (this.roles != null && !this.roles.isEmpty()) ? this.roles : "scope";
	Object claimObj = claimValue(claims, path);
	if (claimObj instanceof List)
	{
	List<Object> listClaim = (List<Object>) claimObj;
	roles = listClaim.stream()
	.map(Object::toString)
	.map(String::intern)
	.collect(Collectors.toList());
	}
	else if (claimObj != null)
	{
	roles = Arrays.asList(claimObj.toString().split(SCOPE_VALUE_PATTERN));
	roles.replaceAll(String::intern);
	}
	Object rolesValue = claimValue(claims, this.roles);
	@SuppressWarnings("unchecked")
	List<String> rolesValueAsList = (rolesValue instanceof List)
	? (List<String>) rolesValue
	: Optional.ofNullable(rolesValue)
	.map(Object::toString)
	.map(s -> s.split("\\s+"))
	.map(Arrays::asList)
	.orElse(null);
	List<String> roles = rolesValueAsList != null
	? rolesValueAsList.stream()
	.map(Object::toString)
	.map(String::intern)
	.toList()
	: null;

[jfallows]

Suggested change

	Map<String, Object> realmAccess = new HashMap<>();
	realmAccess.put("roles", asList("default-roles-backend", "offline_access", "uma_authorization"));
	claims.setClaim("realm_access", realmAccess);
	claims.setClaim("realm_access",
	Map.of("roles", List.of("default-roles-backend", "offline_access", "uma_authorization")));

[jfallows]

This should already default roles to scope in the builder .build() method, so it can be omitted here and still have the value scope in the returned JwtOptionsConfig object.

[jfallows]

Same feedback here.

[jfallows]

Suggested change

	private static final String SCOPE_VALUE_PATTERN = "\\s+";
	private static final String SCOPE_PATH_PATTERN = "\\.";
	private static final String SPLIT_VALUE_PATTERN = "\\s+";
	private static final String SPLIT_PATH_PATTERN = "\\.";

[jfallows]

Can this line be removed since the type of rolesValueAsList is already known to be List<String>, so individual role members are already known to be of type String?