Tests enhancements/new tests for issues found in !29

Changes:

• tnodata2 now has new behavior due to discussion in !27 (merged). It was found that to be compatible with how Octo does nulls now, we need to index pieces where data doesn't exist.
• tnodata3 (in the same vein) needs to index nodes that don't exist.
• Old stats tests changed: tstat -> tstat1
• Added a new tstat2 test per discussion in !21 (comment 645430136).
• Added a new tlsxref2 test per discussion in YottaDB/DBMS/YDBOcto!898 (comment 653213876)
• Added trange[3-5] based on !29 (comment 655310465), !29 (comment 655423162), -- trange3 now disabled because it fails.
• tinv11 tests an invalid subscript range per !29 (comment 655423174)
• tinv12 tests the scenario where a global spans regions, but different regions have different null settings. Per discussion in !29 (comment 654447677). This necessitated changes in tests/test.sh to create a GDE files with these regions.
• Added tcon5 based on !29 (comment 656502384)
• Added tcon6 based on !29 (comment 667811721)
• Add bash based tests in tests/bash-tests/ydbaim_test.sh that run commands via %XCMD and save the output for the purpose of testing interactive command line use with error messages. Output compared to ref file tests/bash-tests/bash_test_output.ref. This exposed an issue.
• The last commit from master added a global called ^%ydbAIMDxref used for metadata. It shouldn't count towards the count of AIM globals. Tag aimgbls adjusted as a result. -- the variable tmp1 in the error trap was not defined. This is now fixed. -- Bash tests CANTADDSTAT, INVPNUMSEP disabled due to regressions, will be re-enabled later after they are fixed.