Make auto completion optional

[Pearl1594]

Fixes: #90
This PR adds a config parameter - autocomplete which defaults to true, but when set to false, turns of auto-completion of arg/parameter values. NOTE: Argument/Parameter name / API name auto-completion still happens.

$ go run cmk.go
Apache CloudStack 🐵 CloudMonkey 6.1.0
Report issues: https://github.com/apache/cloudstack-cloudmonkey/issues

(test) 🐱 > set autocomplete true
(test) 🐱 > 
(test) 🐱 > list accounts id=
04660396-f89e-4d44-a251-0e24176b4b85 (ACSUser)                                                       27e0711a-cf5a-4ecc-8f90-39b794eee2e1 (baremetal-system-account)                                      
3ae0e9b2-d162-4c43-bb3a-241d6cb4f02a (test-a-TestKubernetesCluster-JKHRZF)                           7596929a-f6b6-11eb-9ff7-1e00d500016d (admin)      

                                                   
(test) 🐱 > set autocomplete false
(test) 🐱 > list accounts id=
// Hitting tab doesn't provide list of account ids as it usually does when auto-completion is true

[shwstppr]

@Pearl1594 is it possible to turn it off only for values? Probably that is reporter's concern in the issue for a big environment

[Pearl1594]

@shwstppr autocomplete config parameter affects only listing of argument values, and irrespective of its value, auto-completion will still work for API names and arguments.

[shwstppr]

LGTM. API param values are not shown on tab press

[rohityadavcloud]

LGTM cc @serverchief

[rohityadavcloud]

@Pearl1594 @shwstppr can you test for case where in the cmk config file the new parameter is not define, how does it behave? (for backward compatibility if param is not defined in config we should treat it as true)

[Pearl1594]

Seems like it was an issue when the config wasn't defined. Fixed it - autocomplete now defaults to true if not explicitly defined @rhtyd @shwstppr