Smoothly Embed Vector Bundles into Preexisting Code

[gh-DeRhamSource]

Though, ticket #28159 implemented vector bundles into Sage and is already merged, there are still things to do. Sections and tensor fields share similar or even identical code lines and implementation concepts. This comes in quite unhandy when further modifications are to be made, either to vector bundles or to tensor fields.

This gap should be closed in this ticket. Appropriate inheritances and removing code redundancies will be performed here.

Until this ticket is finished, I suggest one of the following procedures:

1) Every modification either to tensor fields or to sections, should be done for both if intersections occur. This makes the following task devoted to this ticket easier and keeps the code as clean as possible.

2) Link the ticket devoted to possible interactions in the comments of this ticket.

[gh-DeRhamSource]

#28716: Linearly independent vector fields as new frame -> Adaption to Sections

[embray]

Ticket retargeted after milestone closed

[mkoeppe]

Batch modifying tickets that will likely not be ready for 9.1, based on a review of the ticket title, branch/review status, and last modification date.