Merge remote-tracking branch 'origin/release_210'

* origin/release_210: (124 commits)
  Bump version to v2.10.0
  Setting the derived variable support OFF by default
  Add the CURL function to derived variables (#4114)
  Add -f file1 [file2...] option to process adios files from a list instead of a campaign recording
  DataPlane Configuration changes (#4121)
  update doc
  Add attribute support to campaign
  Add a random string to each database name to avoid collision when running multiple applications in the same directory at the same time. Fixes issues with CI that runs ctest in parallel
  Initialize ADIOS::m_UserOption before tentaively calling ProcessUserConfig()
  - set ACA version to  0.1 - remove debug prints - add doc on Campaign Management in Advanced section - change static struct of UserOptions to class member of ADIOS class to make it work with gcc 4.8
  used size_t not int for map indexing to avoid type conversion
  fix remote server test, use the new binary name
  clang-format
  Use the name of the campaign in the cache path to avoid name collision
  rename remote_server to adios2_remote_server
  bug fix: the order of entries in bpdataset table is undefined but the campaign data reader relied on calculating the index as if it was sorted by the insertion order. Use a map instead to store the rowid and use that as index for the bpfile elements.
  Use yaml parser in campaign manager python script
  change a long variable to int64_t to avoid size confusion on windows
  do not include unistd.h
  Fix compiler error Remove extra file not needed
  ...

Author: vicentebolea