Implement TOUCH command

[kelvinmwinuka]

Implement the TOUCH command, which updates the access times of the provided keys.
Reference: https://redis.io/docs/latest/commands/touch/

Client-Server Spec:

Command File: ./internal/modules/generic/commands.go
Test File: ./internal/modules/generic/commands_test.go

Command: touch
Module: constants.GenericModule
Categories: constants.KeyspaceCategory, constants.ReadCategory, constants.FastCategory
Description: (TOUCH key [key ...]) Alters the last access time of a key(s). A key is ignored if it does not exist.
Sync: true

Embedded Spec:

Command File: ./echovault/api_generic.go
Test File: ./echovault/api_generic_test.go

NOTE: You may have to edit the HandlerFuncParams type to include a function that touches the keys.