v1.30.0

Added

• Add aggregate transform [#1924]
• Add constraintext attribute for bar traces [#1931]
• Add axis layer attribute to ternary axes [#1952]
• Add cross-trace matching auto-binning logic to histogram traces [#1944]
• Add data/layout/config api to Plotly.toImage to generate a static
  graph without having to render an interactive graph first [#1939]
• Add nameformat attribute to groupby transforms to set pattern by which
  grouped traces are named [#1919]

Fixed

• Fix hover label exponents [#1932, #1949]
• Fix scatter fill with isolated endpoints [#1933]
• Fix parcoords axis tick scale when ticktext is unordered [#1945]
• Fix sankey with 4 multi-links or more [#1934]
• Fix exponent labels beyond SI prefixes [#1930]
• Fix image generation for marker gradient legend items [#1928]
• Fix parcoords image generation when multiple parcoords graphs
  are present on page [#1947]
• Ignore bare closing tags in pseudo-html string inputs [#1926]