Use shellcheck to check/lint shell scripts

[nichtich]

qa-catalogue includes 63 shell scripts. Several of these can be replaced by config files (#489).

wc -l $(find . -type f -exec head -1 {} /dev/null \;  | awk '/bash/ { print file } { file = $0 } ' | sed 's/[=<> ]//g' )

The rest should be checked with automatic code analysis, e.g. with shellcheck. It's these files with current lines of code:

   23 ./scala/build.sh
  229 ./index
    9 ./setdir.sh.template
   25 ./network-export.sh
  723 ./common-script
   17 ./postprocess-solr
   49 ./docker/qa-catalogue
  114 ./export-network.sh
  130 ./qa-catalogue
   41 ./prepare-solr
  203 ./solr-functions
   12 ./src/main/resources/pica/update-avram-k10plus-title.sh
   11 ./src/main/resources/pica/update-avram-k10plus-subjects.sh
   15 ./avram-schemas/validate-schemas
   56 ./scripts/sqlite/index-issue-details.sh
   63 ./scripts/sqlite/completeness.sqlite.sh
   77 ./scripts/sqlite/calculate-aggregated-numbers.grouped.sh
  148 ./scripts/timeline/timeline.sh
   61 ./scripts/scripts-for-2019-paper/run-all.sh

[nichtich]

Warnings are down to 50, this should be ok. Errors are detected via GitHub action. We have 2000 lines of shell scripts, excluding the individual catalogue config files (which should be replaced by config files IMHO, see #489). The handling of PARAMS could also be changed to use config files instead (see #500).

$ for f in $(git ls-files); do [ -x "$f" ] && grep -q bash "$f" || continue; echo $f; done | grep -v catalogues/ | xargs wc -l | sort -n
   11 src/main/resources/pica/update-avram-k10plus-subjects.sh
   12 src/main/resources/pica/update-avram-k10plus-title.sh
   15 avram-schemas/validate-schemas
   17 postprocess-solr
   22 scala/build.sh
   25 network-export.sh
   40 prepare-solr
   49 docker/qa-catalogue
   55 scripts/sqlite/index-issue-details.sh
   61 scripts/scripts-for-2019-paper/run-all.sh
   63 scripts/sqlite/completeness.sqlite.sh
   76 scripts/sqlite/calculate-aggregated-numbers.grouped.sh
  114 export-network.sh
  130 qa-catalogue
  142 scripts/timeline/timeline.sh
  198 solr-functions
  230 index
  739 common-script
 1999 insgesamt