Implement help messages about label name regex

[manrodrigues]

The name text boxes should be a help message that explains to the user what type of regex must be matched in order for the forward buttons to be enabled

In the case below, the user has no way of knowing that the button is disabled because of the spaces.

This must be implemented for creating and editing all elements

[manrodrigues]

We have two observations here:

• the expected regex is only being displayed after click on the screen. the ideal scenario would be for the event to be the beginning of typing. As soon as the user starts typing the message should start to be shown.

• This is probably derived from my lack of specification in the task. But this regex must be applied to all name labels (groups, policies, sinks, datasets)

[manrodrigues]

@brunofariasdeo I guess we can include a validation for #1509 on your current PR as well.. All the names must be labels larger than 1 character.. so we can keep "next" button disabled if the name have only 1 character and the help message could advertise it.

[manrodrigues]

Closing based on #1492