Support optional resource pack with HST and JWST filters

[petercamps]

Description With this update, the BroadBand class supports an optional resource pack with filters for all HST and JWST bands. See the BroadBand class documentation for a list.

There is also a technical update for the filter definitions that are included by default, without any functional changes.

Resource packs All users must update the Core resource pack to version 7. The HST and JWST bands are available only if the optional ExtraBands resource pack is also installed. See the installation guide for more information.

Example ski file usage In the bandName property of the BroadBand class, specify band filename segments (separated by a space or an underscore) that uniquely identify the band. For example:

<ConfigurableBandWavelengthGrid>
  <bands type="Band">
    <BroadBand bandName="HST FUV F25ND5 G140M"/>
    <BroadBand bandName="HST NICMOS3 F222M"/>
    <BroadBand bandName="HST WFC3_UVIS2_F665N"/>
    <BroadBand bandName="HST F250W"/>
  </bands>
</ConfigurableBandWavelengthGrid>

Or

<ConfigurableBandWavelengthGrid>
  <bands type="Band">
    <BroadBand bandName="NIRCam F410M"/>
    <BroadBand bandName="NIRCam F470N"/>
    <BroadBand bandName="MIRI F770W"/>
    <BroadBand bandName="MIRI F1800W"/>
    <BroadBand bandName="MIRI F2550W"/>
  </bands>
</ConfigurableBandWavelengthGrid>

Motivation This feature was suggested by user Mitali Dale.