Address all golangci-lint v2.10.1 (CI's version) findings:
* Add http.MaxBytesReader hard cap to ParseMultipartForm sites in
rest_private.savePictureCtrl (32MB) and api/migrator (256MB) — fixes
G120 by bounding total request body before form parsing.
* Suppress G70x in CLI subcommands cmd/{backup,cleanup,import,remap}.go:
all four issue HTTP requests against operator-supplied RemarkURL/CLI
flags, never user input. Each suppression carries a one-line reason.
* Suppress G122 in image fs_store cleanup walk: staging directory tree
is server-only, no untrusted symlinks land there.
Timeout, admin password and site id are set in many commands,
and we need to take care of synchronising the descriptions
and flags between them.
This change moves these standard options to cmd.go importing them
in the same manner CommonOpts imported by all commands already.
* WIP: url mapper, wrapped reader approach
* create url mapper on start
* add pattern matching in mapper
* check pattern matching in test
* change site-id from radio-t to remark42 in tests
* create new url mapper on demand, based on given func, union strict and prefix rules
* rename convert to remap
* add import with mapper test
* rename mapper func to UrlMapperMaker, create comments in test via data service
* move /import/wait to /wait ctrl
* add remap cmd
* fix url naming
Dmitry VerkhoturovandUmputun
Anton KosourovandUmputun