fix(remappings): project autoremappings should respect config

[grandizzy]

Motivation

Closes #9454
Project paths remappings were automatically added with PR #9258 in order to solve #3440 but used config key instead value:
For src=src/contracts config, remapping should be src/contracts/ = src/contracts/ (instead src=src/contracts)
For src=src config, remapping should be src/ = src/.

Solution

• add remappings for configured dirs

[zerosnacks]

This looks correct to me, would like one more review as remappings are sensitive

cc @klkvr / @DaniPopes

[mattsse]

makes sense