Fix LineTimeSerieChart tooltip formatting

[ziyang-lin-404]

[bert-e]

Hello ziyang-lin-404,

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[bert-e]

Waiting for approval

The following approvals are needed before I can proceed with the merge:

• the author

• one peer

Peer approvals must include at least 1 approval from the following list:

• @hervedombya

• @JBWatenbergScality

• @ChengYanJin

• @damiengillesscality

• @JeanMarcMilletScality

• @MonPote

[ziyang-lin-404]

/approve

[bert-e]

I have successfully merged the changeset of this pull request
into targetted development branches:

• ✔️ development/1.0

Please check the status of the associated issue None.

Goodbye ziyang-lin-404.

The following options are set: approve