RFR: 8427: Text getting overlapped on graph of Processes screen

[Aymane Harmaz]

When the width of the chart title label exceeds the left margin ( xOffset) reserved for it, the label is truncated without taking into account the width of the y-axis tick labels. This can potentially lead to overlapping between the chart title and the y-axis tick labels.

Currently, the width of the y-axis tick labels is determined at the formatter level and is not dynamically available during chart label truncation.

Two potential workarounds are :

- Increase the xOffset size for the affected chart, allocating enough space to display both the chart title and the tick labels without overlap.
(This impacts only the chart in question.)
- Base Chart title label truncation on a default value for y-axis tick labels, even without access to exact tick widths.
(This impacts all charts.)

I followed the first strategy.

Screenshot of processes page post change : 

<img width="1173" height="343" alt="Screenshot 2025-10-10 at 17 02 40" src="https://github.com/user-attachments/assets/c490525f-b816-4bce-b242-621439ccf22e" />

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Commit messages:
 - 8427: Text getting overlapped on graph of Processes screen

Changes: https://git.openjdk.org/jmc/pull/678/files
  Webrev: https://webrevs.openjdk.org/?repo=jmc&pr=678&range=00
  Issue: https://bugs.openjdk.org/browse/JMC-8427
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jmc/pull/678.diff
  Fetch: git fetch https://git.openjdk.org/jmc.git pull/678/head:pull/678

PR: https://git.openjdk.org/jmc/pull/678