Consultation's budget amounts formatting

[danguita]

Connects to #119.

What does this PR do?

This PR normalizes the budget amounts format across different sections on the UI, taking care of both server and client sides.

In the server side we're using a helper method to wrap the number formatting, while in client side we're propagating the same format options through a numeric format library which is included as a GobiertoBudgetConsultations specific vendor.

How should this be manually tested?

Let's check that any budget amount in the Consultation response process match the following assertions:

assert_equal "124000", budget_amount_to_human(123567)
assert_equal "123000", budget_amount_to_human(123000)
assert_equal "123 M", budget_amount_to_human(123000000)
assert_equal "1.24 M", budget_amount_to_human(1240000)

Final notes

There would be slight differences between the server and client-side number formatting, although I would not care about them since there's an enhancement that will drop any repeated logic at #133.

[ferblape]

👍 Works OK
👍 I agree with your thoughts, no need to worry about that now

Merging!

[danguita]

Cool, thanks!