Incorrect test of expression values

To test if a value is an expression of the form "${my.expression}" AbstractItem uses value.startsWith("${") && value.endsWith("}") but wildfly accepts the $ pattern anywhere in the string, for example some/${my.expression}/directory, but as HAL only validates the start and end of string, then it is incorrect. HAL should accept the latter as a pattern to test if a value is an expression. One example is the "path" attribute of /subsystem=undertow/configuration=handler/file=welcome-content resource.

HAL should fix this in form components and the Expression Resolver dialog (tools menu).