Fail the action when Trello API request fails (e.g., wrong list ID)

Fix infinite PR commenting when github-include-pr-branch-name or github-include-new-card-command are used.

Introduce github-include-pr-commit-messages which scans PR commit messages to find Trello card URLs and comments card URLs to the PR.

Added "Closes" prefix to PR body update when using github-include-new-card-command and github-require-keyword-prefix.

Added "Closes" prefix to automatic comments when using github-include-pr-branch-name and github-require-keyword-prefix.

Introduced new option: github-enable-related-keyword-prefix

When enabled, it ignores Trello URLs prefixed with "Related". Basically it is an alternative approach when you don't want to use github-require-keyword-prefix but still want to link related cards for extra context.

Improve Trello API error logging

Split main.test into smaller files and improved test coverage.

Fixes

• board scope when searching Trello cards
• commenting multiple cards referenced in the branch name

Introduce github-allow-multiple-cards-in-pr-branch-name option which enables to find multiple Trello cards from branch name. For example a branch name feature/38-39-foo-bar includes two short IDs 38 and 39 which are then used to find Trello cards. We recommend to use trello-board-id along with this option to avoid system finding and moving wrong cards who happen to have same short ID (i.e. Trello short IDs are unique only for each board).