feature: Rework network y-axis, linear interpolation for off-screen data

[ClementTsang]

Description

A description of the change and what it does. If relevant (such as any change that modifies the UI), please provide screenshots of the change:

Rewrite of the y-axis labeling and scaling for the network widget, along with more customization. This still has one step to be optimized (cache results so we don't have to recalculate the legend each time), but will be done in another PR for sake of this one being too large already.

Furthermore, this change adds linear interpolation at the 0 point in the case a data point shoots too far back - this seems to have lead to ugly gaps to the left of graphs in some cases, because the left hand limit was not big enough for the data point. We address this by grabbing values just outside the time range and linearly interpolating at the leftmost limit. This affects all graph widgets (CPU, mem, network).

This can be optimized, and will hopefully be prior to release in a separate change.

Current look:

To do:

• Cache computation results if possible Skipped for MVP, I'll do this directly after along with some optimizations
• Details of change
• Documentation changes (TODO: remember to update gif later before release)
• Testing
  • Log
  • Normal/linear
  • Bytes
  • Bits
  • Config file + command line
  • Decimal prefix
  • Binary prefix
  • Resize properly

Issue

If applicable, what issue does this address?

Closes: #96

Type of change

Remove the irrelevant ones:

• New feature (non-breaking change which adds functionality)

Test methodology

If relevant, please state how this was tested:

Furthermore, please tick which platforms this change was tested on:

• Windows
• macOS
• Linux

If relevant, all of these platforms should be tested.

Checklist

If relevant, ensure the following have been met:

• Change has been tested to work, and does not cause new breakage unless intended
• Code has been self-reviewed
• Documentation has been added/updated if needed (README, help menu, etc.)
• Passes CI pipeline (clippy check and cargo test check)
• Areas your change affects have been linted using rustfmt (cargo fmt)
• No merge conflicts arise from the change

Other information

Provide any other relevant information to this change:

[ClementTsang]

As mentioned by the comment, we can probably replace this with OrderedFloat when we do a refactor in regards to the interpolation data structures.

[ClementTsang]

If we switch to getting bytes from harvester, remember to update this too!

[ClementTsang]

This is for the future (i.e. after this PR) to optimize; currently we do this full legend calculation throughout the entire set of data points each redraw cycle PER widget, which sounds costly at full data capacity. Ideally we can re-use some max entry calculations too (or change how we do interpolation + data point storage to make this faster).