bring back the code from tinkerbell/dhcp

[jacobweinstock]

Description

The DHCP library was created in order to provide a mechanism for the DHCP functionality to be written in a very clean and composible way. This was not possible with the previous state of Boots and the personnel involved at that time.

The current state of Smee is ready for this functionality to be returned and placed in a very clean and composable way into the code base.

Moving this functionality back in will improve the development process/experience. It is important to note that we do take on the trade off of not having the combined commit history of the DHCP library within Smee. We won't lose the commit history entirely as the DHCP library GitHub repo will remain (archived) in order to have the commit history available.

Why is this needed

Fixes: #

How Has This Been Tested?

How are existing users impacted? What migration steps/scripts do we need?

Checklist:

I have:

• updated the documentation and/or roadmap (if required)
• added unit or e2e tests
• provided instructions on how to upgrade

[chrisdoherty4]

Given we aren't in the business of maintaining libraries, would you be open to nesting under a top level internal package?

[codecov]

Codecov Report

Attention: 64 lines in your changes are missing coverage. Please review.

Comparison is base (dea4bd4) 28% compared to head (a21ff7d) 68%.

Files	Patch %	Lines
internal/dhcp/dhcp.go	66%	13 Missing and 5 partials ⚠️
internal/dhcp/handler/reservation/handler.go	89%	10 Missing and 6 partials ⚠️
internal/backend/file/file.go	92%	8 Missing and 4 partials ⚠️
internal/backend/kube/kube.go	95%	3 Missing and 3 partials ⚠️
internal/dhcp/handler/reservation/option.go	95%	2 Missing and 2 partials ⚠️
internal/ipxe/script/ipxe.go	0%	4 Missing ⚠️
internal/dhcp/otel/otel.go	98%	1 Missing and 1 partial ⚠️
cmd/smee/main.go	0%	1 Missing ⚠️
internal/backend/kube/error.go	50%	1 Missing ⚠️

Additional details and impacted files

@@         Coverage Diff          @@
##           main   #364    +/-   ##
====================================
+ Coverage    28%    68%   +40%     
====================================
  Files         5     15    +10     
  Lines       481   1297   +816     
====================================
+ Hits        136    893   +757     
- Misses      337    375    +38     
- Partials      8     29    +21     

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