Fixed buttons color at smart contract section.

[YegorSan]

This PR is related to #2652 issue.

Motivation

• Different color of buttons at smart contract page.

Changelog

Bug Fixes

• Fixed color of a "Query" buttons at Read Contract section.

Checklist for your PR

• I added an entry to CHANGELOG.md with this PR
• If I added new functionality, I added tests covering it.
• If I fixed a bug, I added a regression test to prevent the bug from silently reappearing again.
• I checked whether I should update the docs and did so if necessary
• If I added/changed/removed ENV var, I should update the list of env vars in https://github.com/poanetwork/blockscout/blob/master/docs/env-variables.md to reflect changes in the table here https://poanetwork.github.io/blockscout/#/env-variables?id=blockscout-env-variables. I've set master in the Version column.
• If I add new indices into DB, I checked, that they don't redundant with PGHero or other tools

[vbaranov]

@YegorSan should we create a class for those inline styles?

[YegorSan]

@vbaranov As far as I understand , this partial is wrapped in elixir loop action, and each item should be rendered with already added inline style. I do understand, that it's not the best practice (but somebody are saying that it can increase page loading speed). If you confirm, I'll create a unique class for that element.

[vbaranov]

@YegorSan My comment was only about clearance: styles in classes look better than inline styles in the source. My proposed change doesn't affect performance until those styles are loaded asynchronously but we don't load button styles async because they shouldn't visually change styles. Thus, let's leave it as is. But, please, close this PR and create PR to master branch.

[YegorSan]

@vbaranov As you requested, I am closing this PR , and created new one to master branch: #2671