[Feature] Use by default semantical branch name "release/*" for releases

**Is your feature request related to a problem? Please describe.**
Current release-please branch name doesn't follow the Conventional Branch names standard for releases: like `release/*` which can be be improved.

**Describe the solution you'd like**
[Conventional Branches](https://conventional-branch.github.io/#specification) standard suggests to use the `release/*` branch name prefix for releases, for example, `release/v1.2.3`, see below:

> release/: For branches preparing a release (e.g., release/v1.2.0)

Would be nice to follow this specification and adjust the default branch prefix name to follow this standard.

**Describe alternatives you've considered**
None, just matter of improving compliance with ITGC/ISO27001 standards

**Additional context**
Depends on #1167 to make branch prefix configurable

Start by reviewing the release branch-prefix configuration and the related issue #1167, which this request depends on. Confirm how the current default is selected and verify that the default release branch format becomes release/*, such as release/v1.2.3.

Written by the indexing model from the issue text.