[Feature]: Split Renovate configs to distinguish Trunk Based and Mainline strategies

[kpanot]

Context

Currently, the Renovate presets exposed by Otter are defining rules only considering that the user has a repository based on Mainline strategy (with release/* delivered branches).
The purpose of this issue is to support both Trunk Based (where all versions are on a single branch) and Mainline strategies.

Proposal

• Keep in base preset only rules not relative to branching model
• Split rules relative to branch name in 2 presets according to the strategy
• The truck based strategy preset may requires the default branch name (and default to main)