drt: explicit_wrong_dir, no_drv and pin_term/pin_net

[bnmfw]

This PR has some minor changes to prepPoint_pin_checkPoint_planar and prepPoint_pin_checkPoint_viaDir_helper.
There are essentially three changes:

vert_dir, horz_dir and wrong_dir made explicit

Throughout both functions an at least on if statement has to check whether the given dir is in the preferred direction of the layer. This check is verbose and makes it difficult to follow the part of the code where those checks exists. wrong_dir was created to facilitate legibility.

pin_term and pin_net variables

Multiple getters for this variables though the code make it more bloated. Accessing them once and using them further make the code smaller.

no_drv

Both no_drv changes are very simple. In both cases the variable is checked, if true something happens using true as an argument (either setting the variable itself or ap->setAccess()), if false the same happens using false. no_drv is now used directly. There is no loss in readability since no_drv is defined right before both cases.
One could argue that no_drv is unnecessary, and its condition could be used in its place, but I'd argue that the no_drv labeling makes its meaning more clear

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"