ui: transactions page - transaction query column partial txn queries not being displayed when there are missing statements

[xinhaoz]

To construct transaction query text, we map the txn's stmt fingerprints to their queries. Sometimes, we won't be able to find a statement for a txn. This leads to 2 issues:

1. By the transaction text, there's no way to tell if a stmt's query was skipped. We might want to add a placeholder text indicating that.
2. When constructing the transaction query text column, we limit the text shown to 200 characters. When we construct the txn step mentioned previously, we join each stmt query with a newline character. Due to missing statements, we may truncate the text to only whitespace if the first N queries are missing (see photo below as an example). Addressing 1 would fix this. We can ensure that missing queries don't produce newline characters.

Jira issue: CRDB-43855

[blathers-crl[bot]]

Hi @xinhaoz, please add branch-* labels to identify which branch(es) this C-bug affects.

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