Adds error handling for undefined/null password field in authentication-local

[mohitmayank]

Steps to reproduce the issue

• Create a feathers app with authentication using CLI
• Send a local auth request but without password field.

Expected behavior

Should throw 401: NotAuthenticated

Actual behavior

Following 500: GeneralError gets thrown

error: Error: Illegal arguments: undefined, string                                                                                    
    at _async (/<root>/node_modules/bcryptjs/dist/bcrypt.js:286:46)
    at /<root>/node_modules/bcryptjs/dist/bcrypt.js:307:17                                                                                             
    at new Promise (<anonymous>)                                                       
    at Object.bcrypt.compare (/<root>/node_modules/bcryptjs/dist/bcrypt.js:306:20)                                                                     
    at LocalStrategy.<anonymous> (/<root>/node_modules/@feathersjs/authentication-local/lib/strategy.js:88:53)                                         
    at Generator.next (<anonymous>)                                                    
    at /<root>/node_modules/@feathersjs/authentication-local/lib/strategy.js:8:71                                                                      
    at new Promise (<anonymous>)                                                       
    at __awaiter (/<root>/node_modules/@feathersjs/authentication-local/lib/strategy.js:4:12)                                                          
    at LocalStrategy.comparePassword (/<root>/node_modules/@feathersjs/authentication-local/lib/strategy.js:78:16)
    at LocalStrategy.<anonymous> (/<root>/node_modules/@feathersjs/authentication-local/lib/strategy.js:106:24)                                        
    at Generator.next (<anonymous>)                                                    
    at fulfilled (/<root>/node_modules/@feathersjs/authentication-local/lib/strategy.js:5:58)                                                          
    at processTicksAndRejections (internal/process/task_queues.js:97:5)  

[mohitmayank]

@daffl

[daffl]

Thank you!