Rework SOT package names/descriptions & add 3D models

[ubruhin]

SUMMARY

• Fix SOT package naming & dimension inconsistencies
  • Name all SOT packages (SOT23, SOT223, SOT353) according IPC7351C (resp. the Library Expert naming conventions). With the only difference that the lead width is also appended to the name, which was already the case for the SOT223 package.
  • Make package descriptions more descriptive and add more information (e.g. body dimensions) for easier comparison with datasheets.
  • Fix small deviations of lead drawings on the documentation layer to comply with the exact package dimensions.
  • Apply a few very small improvements to legend polygons.
• Add 3D models generated by Add script to generate 3D models for SOT packages LibrePCB/librepcb-parts-generator#122

DATASHEETS / REFERENCES

None

OPEN QUESTIONS / UNRESOLVED ISSUES

None

CHECKLIST

• I have read and followed the library conventions¹.
• For packages, I followed IPC7351C (see details in library conventions).
• For modified elements, I bumped their version number².
• I already used the new library elements in a design and verified their correctness (optional).
• I'm the copyright owner of the added content (i.e. the changes are made by myself, not copied/imported from somewhere else).
• I agree to publish all my changes under the CC0 Public Domain License³, allowing everyone to use and modify the content without any restrictions.

¹ Library Conventions: https://docs.librepcb.org/#libraryconventions
² Minor version bump if only metadata was modified (e.g. "0.1" -> "0.1.1"), major version bump if functional changes were made (e.g. "0.1" -> "0.2")
³ CC0 Public Domain License: https://en.wikipedia.org/wiki/CC0