arrow

ARROW-15693: [Dev] Update crossbow templates to use master or main (#13975)

# Overview

This pull request:

1. Removes hard-coded dependencies on "master" as the default branch name in the crossbow infrastructure and CI template files.

# Implementation

1. Removed comment/text references to "master" branch, including URLs to other repositories.
2. Modified `core.py` to add a new `default_branch` property and a new method `is_default_branch`, for checking whether on the default branch, to the `Target` class.
3. Modified CI template files to use the new `is_default_branch` function to check whether on the default branch.

# Testing

1. Using [lafiona/crossbow](https://github.com/lafiona/crossbow) as a queue repository for qualification.
2. Ran modified template jobs. All failures appeared to be unrelated to the changes.
3. The branch names for all relevant qualification jobs are prefixed with `build-34-*`. 
4. Example of a passing job: [https://github.com/lafiona/crossbow/actions/runs/2920227769](https://github.com/lafiona/crossbow/actions/runs/2920227769)
5. Example of a failing job: [https://github.com/lafiona/crossbow/runs/7998190113](https://github.com/lafiona/crossbow/runs/7998190113) - in this example, the *"Push Docker Image"* workflow step is not included, since we are not on the default branch. The failure appears to be related to issues fetching R package resources and not related to the default branch checking logic. There were a variety of other kinds of failures, but none of them appear related to the default branch checking logic.

# Future Directions

1. Remove "master" from `default_branch` name property of `Target` class.
2. Remove all remaining uses of "master" terminology in crossbow.
3. [ARROW-17512](https://issues.apache.org/jira/browse/ARROW-17512): Address minor issues with crossbow documentation.

# Notes

1. Thank you to @lafiona for her help with this pull request!
2. Due to unexpected technical issues, we opened this pull request as a follow up to https://github.com/apache/arrow/pull/13750. Please see https://github.com/apache/arrow/pull/13750 for more discussion regarding qualification efforts.

Lead-authored-by: Kevin Gurney <kgurney@mathworks.com>
Co-authored-by: Fiona La <fionala7@gmail.com>
Signed-off-by: Alessandro Molina <amol@turbogears.org>