[fix] correct table-function, table-valued-function, and SQL-statement doc errors

[boluor]

Summary

Fixes 23 small documentation issues across the table-functions, table-valued-functions, and SQL-statement (account-management, cluster-management) references. Each item below is independent.

table-functions

• explode-bitmap.md — a stray sentence describing the outer-variant behavior was sitting in the non-outer doc; removed.
• explode-outer.md — frontmatter title was "EXPLODE-OUTER" (hyphen); corrected to "EXPLODE_OUTER". The Syntax line and three lateral-view examples invoked explode(...) rather than explode_outer(...); corrected.
• explode-json-array-int-outer.md — Description referenced explode (non-outer) instead of explode_outer.
• explode-map.md — Examples 1 and 2 invoked explode_map_outer(...) in this non-outer doc; changed to explode_map(...).
• unnest.md — Example 3's result table had columns labeled ord / tag swapped vs the underlying values; header labels reordered. Also frontmatter language: \"en-US\" → \"en\".

table-valued-functions

• frontends.md — Return Value table was missing the CurrentConnected field; added.
• numbers.md — Syntax [, \"<const_value>\" = \"<const_value>\" ] placed the placeholder on the KEY side; the KEY is the literal string \"const_value\". Corrected.
• local.md — a stray fragment +---+---+---+ immediately followed by an orphan closing fence; removed.
• query.md — a result block was opened with a plain fence (no language hint); changed totext for consistency with sibling docs.

sql-statements

• ALTER-WORKLOAD-POLICY.md — frontmatter description and body said "Workload Group" (this doc is for Workload Policy); corrected. Code fence tagged as Java for a SQL example; corrected to sql.
• REVOKE-FROM.md — access-control note text said "perform the GRANT operation"; corrected to "perform the REVOKE operation".
• ALTER-USER.md — garbled sentence \"This command give over supports modifying user roles from versions 2.0…\" rewritten as \"Starting from version 2.0, this command no longer supports modifying user roles…\". Two full-width pipes ｜ in the PASSWORD_LOCK_TIME syntax / description block replaced with ASCII |.
• CREATE-USER.md — same full-width-pipe fix in the same syntax block.
• ALTER-WORKLOAD-GROUP.md / CREATE-WORKLOAD-GROUP.md — a full-width comma ， in English prose replaced with ASCII , and .
• CREATE-RESOURCE.md — parameter table heading read 1.\`but the immediately following text describes`; corrected.
• ADD-BROKER.md — Syntax \"host>:<ipc_port>\" was missing the opening <; corrected. Two examples omitted the required <broker_name> argument; added a placeholder name.
• ADD-BACKEND.md — Usage Notes list had two items both numbered 3.; renumbered the trailing items.
• DROP-USER.md — Syntax wrapped the <user_identity> placeholder in extra single quotes; removed for consistency with the other account-management docs.
• SHOW-COMPUTE-GROUPS.md — result-table header column widths were off by 1, so the pipes didn't align with the rulers; corrected.

Test plan

• CI doc build passes
• Spot-check the affected pages render correctly (titles, fixed examples, added frontends row, syntax punctuation, list numbering, aligned compute-groups result table)