Kintree

MAJOR RELEASE

New features
- Supplier/manufacturer alternates
- On main GUI window, added an option for adding supplier and/or manufacturer alternate to an InvenTree part
- When this option is enabled, the part creation flow is simplified to adding the supplier/manufacturer data to an already exisiting InvenTree part using its ID or IPN field
- This option only works with InvenTree parts as the concept of supplier/manufacturer alternates does not exists (yet) in KiCad
- Manufacturer name match
- Some suppliers use slightly different names for the same manufacturer
- Added a method to ratio compare with existing manufacturers in the database and find potential match
- If match is found, use it. This avoids creating duplicate of the same manufacturer.

Major maintenance
- SnapEDA API moved from Heroku to my own hosting service
- SnapEDA API requires token which cannot be exposed publicly therefore a proxy is needed for SnapEDA API requests
- Heroku dropped the free option and was running an instance of [API proxy server](https://github.com/MauricioRobayo/API-Key-Proxy-Server) which now archived, therefore I have made my own proxy server and run it on `snapeda.eeinte.ch`
- SnapEDA search API was updated to use the new URL, eg. transparent change change to Ki-nTree users
- Updated README, fixes 97
- Updated Python version support to 3.9+ to match InvenTree's own Python version requirements
- Updated dependencies
- Slightly improved test coverage

Maintenance Release
* 92: Remember the last selected supplier
* Fix 94: Resolved match for manufacturer parts when checking for existing InvenTree parts
* Fix 97: Updated parameter fetching and handling
* (Should) Fix 96: Updated [Digi-Key API](https://github.com/peeter123/digikey-api) to `1.0.0` removing support for API v2
* Updated InvenTree Python API and other dependencies

Maintenance Release
All changes from 89
* Upped supported versions of Python from `3.7-3.9` to `3.8-3.10`
* Upped supported InvenTree Python library to `0.7.1`
* Upped various dependencies
* Tiny CI clean-up and capacitor template correction

Maintenance Release

* Fix LCSC API data download - 83
* Add setting to automatically create missing sub-category - 86
* Add documentation for starting a new InvenTree setup from scratch - 80
* Add documentation for InvenTree permissions - 82

Maintenance Release

* Improved image download, see 77
* Switched from `request` to `urllib.request` library
* Added User-Agent support, for URL not resolving without
* Only two tries for the image download: first without (Digi-Key) then with User-Agent (Mouser & LCSC)
* Improved part compare with existing parts, see 78
* Compare with parts from the same category tree, not the parent category
* Prevent comparing parts with empty parameters (they were matching)
* For parts with empty parameters, also check the manufacturer data to avoid duplicates when searching the same MPN with different suppliers

KiCad v6

With the [release of KiCad version 6](https://www.kicad.org/blog/2021/12/KiCad-6.0.0-Release/), KiCad changed the symbol file format from combination of couple of files (`.lib`+`.dcm`) to a single, s-expression file (`.kicad_sym`). The KiCad library reader and writer tool was imported from [KiCad's library utils repository](https://gitlab.com/kicad/libraries/kicad-library-utils).

Because of limited maintenance bandwidth, Ki-nTree versions `0.5.x` and newer will only support KiCad version **6**. To keep using Ki-nTree with KiCad version **5**, use older `0.4.x` versions (pip install kintree==0.4.8).

This release also updated all dependencies and corrected the retrieval of Digi-Key categories due to a change of the Digi-Key API output.