feat(network): Add option to change network unit type

[Cationiz3r]

What type of PR is this? (check all applicable)

• Refactor
• Feature
• Bug Fix
• Optimization
• Documentation Update
• Other: Replace this with a description of the type of this PR

Description

As a continuation of PR #2859, an option metric-units (enabled by default) is added to the internal/network module to make it possible to choose whether 1000 or 1024 should be used to divide the network volume.

Related Issues & Documents

Documentation (check all applicable)

• This PR requires changes to the Wiki documentation (describe the changes)
• This PR requires changes to the documentation inside the git repo (please add them to the PR).
• Does not require documentation changes

The documentation update is included in the feature/network-unit-types branch of the repository https://github.com/Cationiz3r/polybar.wiki.git