Add null check for textJsonElement in WxCpUserGsonAdapter

[zhfkt]

For some Enterprise Wechat endpoints, attrJsonElement.getAsJsonObject().get("text"); return null if there is no field text in attrJsonElement. We need to check null value before getAsJsonObject.

[Copilot]

Pull Request Overview

This PR adds a null check around the text JSON element in buildExtraAttrs to prevent a potential NPE when attrJsonElement has no "text" field.

• Introduced textJsonElement local variable and guard clauses.
• Wrapped attr.setTextValue(...) in an if that verifies the element is non-null and an object.
• Removed the previous direct call to getAsJsonObject().get("text").

Comments suppressed due to low confidence (1)

weixin-java-cp/src/main/java/me/chanjar/weixin/cp/util/json/WxCpUserGsonAdapter.java:130

• Add a unit test for the case where attrJsonElement has no "text" field to verify that buildExtraAttrs handles missing text correctly.

          JsonElement textJsonElement = attrJsonElement.getAsJsonObject().get("text");