Missing locale string when creating vote lock

**Describe the bug**
There's a missing locale string in the create lock modal.

There's no indication of the benefit of staking for a longer period, there should be an obvious notice of the vote multiplier you get for committing your funds to a longer staking period.

**To Reproduce**
Go to voting page
Click on create lock
Hover cursor over the drop down

**Expected behavior**
A clear and concise description of what you expected to happen.

**Screenshots**

**Additional context**
Fixing this could increase the amount of BTS staked.

Start at the voting page's create lock modal and inspect how the dropdown content and locale strings are assembled. Confirm the staking-period vote multiplier notice is displayed in the modal and that its locale string is available; verify the flow manually using the reproduction steps.

Written by the indexing model from the issue text.