_initial_invalid_state not reset to true on searchFilesInitialize

[joaquin-freepik]

Issue report

Brief description of issue

Code in searchFilesInitialize expects _initial_invalid_state to be true before making an API call. This flag is set to true in the constructor. After a first call to searchFilesInitialize everything works correctly, you can call afterwards getNextResponse, getPreviousResponse, etc.

However if you try to start a new search with the SearchFiles object calling again searchFilesInitialize, you will not be able to use getNextResponse, getPreviousResponse, etc. because searchFilesInitialize doesn't reset _initial_invalid_state to true.

Proposed fix (if applicable)

Add _initial_invalid_state = true; add the end of searchFilesInitialize.