feat: Add symlog scale, scattermap zoom fix, and line dash support

[DhruvGarg111]

This PR addresses three issues:

1. Fixes [BUG]: Default zoom and center for scattermap traces does not show all points #7674 (Scattermap Zoom): Implemented auto-calculation for \zoom\ and \center\ in \scattermap\ traces when they are not provided by the user. It now computes the bounding box of the data and fits the map view accordingly.
2. Fixes add symmetrical log scale #221 (Symlog Scale): Added a new axis type \symlog\ (symmetrical log). This uses an \�sinh\ transformation to allow log-like scaling that passes smoothly through zero and handles negative numbers.
3. Fixes [Feature Request] Support line styles in Scattermapbox #6791 (Line Dash): Added support for \line.dash\ in \scattermap\ and \scattermapbox\ traces, mapping Plotly dash strings (e.g. 'dot', 'dashdot') to Mapbox's \line-dasharray\ format.

Changes:

• Modified \src/plots/map/layout_defaults.js\ for auto-bounds.
• Modified \src/plots/cartesian/set_convert.js\ and \layout_attributes.js\ for \symlog.
• Modified \�ttributes.js\ and \convert.js\ in \src/traces/scattermap\ and \src/traces/scattermapbox\ for dashed lines.

[emilykl]

Hi @DhruvGarg111, thanks for the contribution!

Could you split your work into separate PRs for each issue?

To address the individual issues:

• Map zoom and center: I would recommend to hold off further work for now — another contributor is working on a fix in Dynamic map defaults #7692 which looks promising and I'd like to give them the chance to pursue it.

• symlog axis type: Doesn't seem to be quite working yet but I encourage you to open a separate PR and keep working on it. You'll want to add an image test by adding a .json file under test/image/mocks/ which shows an example of the symlog axis type in action.

• line styles in scattermapbox: Likewise doesn't seem to be working yet but feel free to open a separate PR and continue work.

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I'm going to close this PR but please open separate PRs for either or both of the latter two issues if you'd like to keep working on them!