Replacement for fulltest2 builder

We need a replacement for the old buildbot's fulltest2/fulltest2-protocols builder.

It could be a new builder, or x86-debian-12 can be converted into this.

Build specifics:

• i386-based builder, with the newer compiler the better, but stable and able to build all not EOL-ed versions, including 10.5
• source build, no packages
• feature-complete debug build:

  cmake . -DCMAKE_BUILD_TYPE=Debug -DWITH_EMBEDDED_SERVER=1 -DHAVE_EMBEDDED_PRIVILEGE_CONTROL=1 -DWITH_DBUG_TRACE=OFF

  with all compression providers, engines which agree to build on 32-bit, etc.

Tests:

Note: everywhere in this text "default test set" means that no tests or suites are listed on the command line, either as included or excluded, MTR collects tests and suites itself.

• "Normal": default test set
• "Hashicorp": hashicorp plugin tests with --big

  --suite=vault --parallel=1 --big

  It needs the hashicorp vault to be installed and configured. The old buildbot does it dynamically, the script is in the repository. Alternatively it can be pre-installed, but still some configuration will be needed every time – opening the vault etc.
  In the old bb, takes a couple minutes, including configuration.
  Better not to run in parallel.

• "Extra": some non-default suites with "big"

  --suite=jp,spider,spider/bg,engines/funcs,engines/iuds --big

  can be run in parallel, but keep in mind that spider is very demanding in terms of resources, it can run many servers at once

• "Optimizer trace": main suite with optimizer trace enabled

  --suite=main --mysqld=--optimizer_trace=enabled=on

• "Embedded": default test set with the embedded server

  --embedded-server

• "PS protocol": default test set with the PS protocol

  --ps-protocol

• "View protocol": main test suite with the view protocol

  --view-protocol --suite=main

• "PS embedded": default test set with the embedded server and PS protocol

  --ps --embedded

It would also be good to add S3 suite here (e.g. to "Extra" step), otherwise there will be a separate task for it.

Steps can be recombined for optimization, as long as nothing is lost. They can also be run as two or more separate builders if you so prefer, currently in the old bb they are split into two.

Depending on how long they end up to be, we can later add more test steps there, but these must be present.

Please don't name it "fulltest2", make it more sensible, like x86-fulltest, or x86-debug-fulltest, or x86-debian-12-fulltest-debug, whatever.