Merge branch 'ar/submodule-gitdir-tweak'

Avoid local submodule repository directory paths overlapping with each other by encoding submodule names before using them as path components. * ar/submodule-gitdir-tweak: submodule: detect conflicts with existing gitdir configs submodule: hash the submodule name for the gitdir path submodule: fix case-folding gitdir filesystem collisions submodule--helper: fix filesystem collisions by encoding gitdir paths builtin/credential-store: move is_rfc3986_unreserved to url.[ch] submodule--helper: add gitdir migration command submodule: allow runtime enabling extensions.submodulePathConfig submodule: introduce extensions.submodulePathConfig builtin/submodule--helper: add gitdir command submodule: always validate gitdirs inside submodule_name_to_gitdir submodule--helper: use submodule_name_to_gitdir in add_submodule