Online DDL: fix 'vtctlclient OnlineDDL' template queries

[shlomi-noach]

Description

At some point the behavior of sqlparser.QueryMatchesTemplates(...) changed such that if the template has multiple recurring 'val' values, the new behavior expects them to be equal.

This breaks the vtctlclient OnlineDDL behavior, because OnlineDDL's query templates used recurring 'val'. The templates are now updated, and a new unit test validates their behavior.

Related Issue(s)

#11893
#6926

Checklist

• "Backport to:" labels have been added if this change should be back-ported
• Tests were added or are not required
• Documentation was added or is not required

Deployment Notes

[vitess-bot]

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[deepthi]

@shlomi-noach can you (when you get a chance), create a smaller issue for this specific bug and link it to this PR?
I assume that the unit tests you have created mean that we don't need to actually trace this back to when it changed.

[shlomi-noach]

@deepthi I will create an issue tomorrow, sorry for not doing this upfront. I haven't investigated yet where the behavior has changed. The new unit test protects Online DDL 's VExec against further behavior changes.

[shlomi-noach]

Fixes #11893

[shlomi-noach]

Backport to v15: #11951