(#1569) Generify part of `org.cactoos.scalar` package

[rocket-3]

For #1569.

Relaxed parameter types by adding wildcards in constructors of classes of org.cactoos.scalar package (first 9 classes in ABC order):

• And
• AndInThreads
• AndWithIndex
• FirstOf
• IoChecked
• ItemAt
• NoNulls
• PropertiesOf
• Repeated

[rocket-3]

@0crat status

[rocket-3]

@0crat status

[victornoel]

@rocket-3 I'm a bit confused between this PR and #1626, are they solving the same todo? If yes, the process should be:

• do a todo, potentially part of the job if it takes more than 30 mn
• if the todo is not finished, update the todo (effectively deleting the previous todo and defining a new one) and let the 0pdd bot create a ticket, let 0crat assign a dev to it (maybe not you)
• if the todo is finished, just delete the todo

In both case your job is done, the issue is closed by 0pdd and you get the "points". Note that both your PRs seems to update the todo in a different way, this will create merge conflicts, so now that this is done, one of the PR should not touch it and the other should either delete it or update it if there is more work to do (on top of the two PRs).

[0crat]

@sereshqua/z please review this job completed by @andreoss/z, as in §30; the job will be fully closed and all payments will be made when the quality review is completed

[0crat]

Code review was too long (58 days), architects (@victornoel) were penalized, see §55

[sereshqua]

@0crat quality bad